20578974521 has 8 divisors (see below), whose sum is σ = 24902288640. Its totient is φ = 16601525568.

The previous prime is 20578974517. The next prime is 20578974539. The reversal of 20578974521 is 12547987502.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 20578974521 - 2² = 20578974517 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 20578974521.

It is not an unprimeable number, because it can be changed into a prime (20578974511) 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, 86466161 + ... + 86466398.

It is an arithmetic number, because the mean of its divisors is an integer number (3112786080).

Almost surely, 2^20578974521 is an apocalyptic number.

It is an amenable number.

20578974521 is a deficient number, since it is larger than the sum of its proper divisors (4323314119).

20578974521 is a wasteful number, since it uses less digits than its factorization.

20578974521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 172932583.

The product of its (nonzero) digits is 1411200, while the sum is 50.

The spelling of 20578974521 in words is "twenty billion, five hundred seventy-eight million, nine hundred seventy-four thousand, five hundred twenty-one".