651420 has 144 divisors (see below), whose sum is σ = 2515968. Its totient is φ = 132480.

The previous prime is 651401. The next prime is 651437. The reversal of 651420 is 24156.

It is a happy number.

651420 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a junction number, because it is equal to n+sod(n) for n = 651393 and 651402.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 651420.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 13837 + ... + 13883.

It is an arithmetic number, because the mean of its divisors is an integer number (17472).

2⁶⁵¹⁴²⁰ is an apocalyptic number.

651420 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 651420, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1257984).

651420 is an abundant number, since it is smaller than the sum of its proper divisors (1864548).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

651420 is a wasteful number, since it uses less digits than its factorization.

651420 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 80 (or 75 counting only the distinct ones).

The product of its (nonzero) digits is 240, while the sum is 18.

The square root of 651420 is about 807.1059410016. The cubic root of 651420 is about 86.6869446305.

Adding to 651420 its reverse (24156), we get a palindrome (675576).

Subtracting from 651420 its reverse (24156), we obtain a square (627264 = 792²).

It can be divided in two parts, 65 and 1420, that added together give a triangular number (1485 = T₅₄).

The spelling of 651420 in words is "six hundred fifty-one thousand, four hundred twenty".