61504021566 has 48 divisors (see below), whose sum is σ = 144988915344. Its totient is φ = 18729211392.

The previous prime is 61504021559. The next prime is 61504021613. The reversal of 61504021566 is 66512040516.

61504021566 is a `hidden beast` number, since 6 + 1 + 50 + 40 + 2 + 1 + 566 = 666.

It is a self number, because there is not a number n which added to its sum of digits gives 61504021566.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1332136 + ... + 1377531.

It is an arithmetic number, because the mean of its divisors is an integer number (3020602403).

Almost surely, 2^61504021566 is an apocalyptic number.

61504021566 is an abundant number, since it is smaller than the sum of its proper divisors (83484893778).

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

61504021566 is a wasteful number, since it uses less digits than its factorization.

61504021566 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2709785 (or 2709782 counting only the distinct ones).

The product of its (nonzero) digits is 43200, while the sum is 36.

The spelling of 61504021566 in words is "sixty-one billion, five hundred four million, twenty-one thousand, five hundred sixty-six".