21079958578 has 16 divisors (see below), whose sum is σ = 36456871680. Its totient is φ = 8954318016.

The previous prime is 21079958573. The next prime is 21079958591. The reversal of 21079958578 is 87585997012.

It is not an unprimeable number, because it can be changed into a prime (21079958573) 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, 6660858 + ... + 6664021.

It is an arithmetic number, because the mean of its divisors is an integer number (2278554480).

Almost surely, 2^21079958578 is an apocalyptic number.

21079958578 is a deficient number, since it is larger than the sum of its proper divisors (15376913102).

21079958578 is a wasteful number, since it uses less digits than its factorization.

21079958578 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13325001.

The product of its (nonzero) digits is 12700800, while the sum is 61.

The spelling of 21079958578 in words is "twenty-one billion, seventy-nine million, nine hundred fifty-eight thousand, five hundred seventy-eight".