615720 has 64 divisors (see below), whose sum is σ = 2113920. Its totient is φ = 140544.

The previous prime is 615709. The next prime is 615721. The reversal of 615720 is 27516.

It is a super-2 number, since 2×615720² = 758222236800, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is not an unprimeable number, because it can be changed into a prime (615721) by changing a digit.

615720 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 15 ways as a sum of consecutive naturals, for example, 474 + ... + 1206.

It is an arithmetic number, because the mean of its divisors is an integer number (33030).

2⁶¹⁵⁷²⁰ is an apocalyptic number.

615720 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 615720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1056960).

615720 is an abundant number, since it is smaller than the sum of its proper divisors (1498200).

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

615720 is a wasteful number, since it uses less digits than its factorization.

615720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 754 (or 750 counting only the distinct ones).

The product of its (nonzero) digits is 420, while the sum is 21.

The square root of 615720 is about 784.6782780223. The cubic root of 615720 is about 85.0735234671.

The spelling of 615720 in words is "six hundred fifteen thousand, seven hundred twenty".