61565720 has 32 divisors (see below), whose sum is σ = 139453920. Its totient is φ = 24460800.

The previous prime is 61565717. The next prime is 61565729. The reversal of 61565720 is 2756516.

It is a happy number.

It is a Smith number, since the sum of its digits (32) coincides with the sum of the digits of its prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61565729) 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, 944 + ... + 11136.

It is an arithmetic number, because the mean of its divisors is an integer number (4357935).

Almost surely, 2^61565720 is an apocalyptic number.

It is an amenable number.

61565720 is an abundant number, since it is smaller than the sum of its proper divisors (77888200).

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

61565720 is a wasteful number, since it uses less digits than its factorization.

61565720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10355 (or 10351 counting only the distinct ones).

The product of its (nonzero) digits is 12600, while the sum is 32.

The square root of 61565720 is about 7846.3826060166. The cubic root of 61565720 is about 394.8628910451.

The spelling of 61565720 in words is "sixty-one million, five hundred sixty-five thousand, seven hundred twenty".