55615720 has 32 divisors (see below), whose sum is σ = 126904320. Its totient is φ = 21931840.

The previous prime is 55615697. The next prime is 55615723. The reversal of 55615720 is 2751655.

It is a super-2 number, since 2×55615720² = 6186216622236800, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (55615723) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6952 + ... + 12631.

It is an arithmetic number, because the mean of its divisors is an integer number (3965760).

Almost surely, 2^55615720 is an apocalyptic number.

It is an amenable number.

55615720 is an abundant number, since it is smaller than the sum of its proper divisors (71288600).

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

55615720 is a wasteful number, since it uses less digits than its factorization.

55615720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19665 (or 19661 counting only the distinct ones).

The product of its (nonzero) digits is 10500, while the sum is 31.

The square root of 55615720 is about 7457.5947865247. The cubic root of 55615720 is about 381.7091066841.

The spelling of 55615720 in words is "fifty-five million, six hundred fifteen thousand, seven hundred twenty".