61565660 has 48 divisors (see below), whose sum is σ = 140597856. Its totient is φ = 22509312.

The previous prime is 61565657. The next prime is 61565711. The reversal of 61565660 is 6656516.

It is a self number, because there is not a number n which added to its sum of digits gives 61565660.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 26714 + ... + 28926.

It is an arithmetic number, because the mean of its divisors is an integer number (2929122).

Almost surely, 2^61565660 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 61565660, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (70298928).

61565660 is an abundant number, since it is smaller than the sum of its proper divisors (79032196).

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

61565660 is a wasteful number, since it uses less digits than its factorization.

61565660 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2342 (or 2340 counting only the distinct ones).

The product of its (nonzero) digits is 32400, while the sum is 35.

The square root of 61565660 is about 7846.3787825977. The cubic root of 61565660 is about 394.8627627714.

The spelling of 61565660 in words is "sixty-one million, five hundred sixty-five thousand, six hundred sixty".