615420 has 72 divisors (see below), whose sum is σ = 2018016. Its totient is φ = 150912.

The previous prime is 615413. The next prime is 615427. The reversal of 615420 is 24516.

615420 = 104² + 105² + ... + 143².

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (615413) and next prime (615427).

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 = 615393 and 615402.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (615427) by changing a digit.

615420 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 2209 + ... + 2471.

It is an arithmetic number, because the mean of its divisors is an integer number (28028).

2⁶¹⁵⁴²⁰ is an apocalyptic number.

615420 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 615420, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1009008).

615420 is an abundant number, since it is smaller than the sum of its proper divisors (1402596).

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

615420 is a wasteful number, since it uses less digits than its factorization.

615420 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 291 (or 286 counting only the distinct ones).

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

The square root of 615420 is about 784.4870935841. The cubic root of 615420 is about 85.0597043051.

Adding to 615420 its reverse (24516), we get a palindrome (639936).

It can be divided in two parts, 615 and 420, that added together give a triangular number (1035 = T₄₅).

The spelling of 615420 in words is "six hundred fifteen thousand, four hundred twenty".