72121564566 has 48 divisors (see below), whose sum is σ = 162183909888. Its totient is φ = 24020793000.

The previous prime is 72121564549. The next prime is 72121564633. The reversal of 72121564566 is 66546512127.

72121564566 is a `hidden beast` number, since 7 + 2 + 1 + 21 + 5 + 64 + 566 = 666.

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, 537991 + ... + 658541.

It is an arithmetic number, because the mean of its divisors is an integer number (3378831456).

Almost surely, 2^72121564566 is an apocalyptic number.

72121564566 is an abundant number, since it is smaller than the sum of its proper divisors (90062345322).

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

72121564566 is a wasteful number, since it uses less digits than its factorization.

72121564566 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 121799 (or 121787 counting only the distinct ones).

The product of its digits is 604800, while the sum is 45.

The spelling of 72121564566 in words is "seventy-two billion, one hundred twenty-one million, five hundred sixty-four thousand, five hundred sixty-six".