651240 has 96 divisors (see below), whose sum is σ = 2227680. Its totient is φ = 171072.

The previous prime is 651239. The next prime is 651247. The reversal of 651240 is 42156.

It is a happy number.

It is a super-2 number, since 2×651240² = 848227075200, which contains 22 as substring.

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

It is not an unprimeable number, because it can be changed into a prime (651247) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 9687 + ... + 9753.

It is an arithmetic number, because the mean of its divisors is an integer number (23205).

2⁶⁵¹²⁴⁰ is an apocalyptic number.

651240 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 651240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1113840).

651240 is an abundant number, since it is smaller than the sum of its proper divisors (1576440).

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

651240 is a wasteful number, since it uses less digits than its factorization.

651240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 93 (or 77 counting only the distinct ones).

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

The square root of 651240 is about 806.9944237726. The cubic root of 651240 is about 86.6789594660.

Adding to 651240 its reverse (42156), we get a palindrome (693396).

The spelling of 651240 in words is "six hundred fifty-one thousand, two hundred forty".