10921815778 has 16 divisors (see below), whose sum is σ = 16924564224. Its totient is φ = 5280572880.

The previous prime is 10921815731. The next prime is 10921815797. The reversal of 10921815778 is 87751812901.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 10201 + ... + 148147.

It is an arithmetic number, because the mean of its divisors is an integer number (1057785264).

Almost surely, 2^10921815778 is an apocalyptic number.

10921815778 is a deficient number, since it is larger than the sum of its proper divisors (6002748446).

10921815778 is a wasteful number, since it uses less digits than its factorization.

10921815778 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 139257.

The product of its (nonzero) digits is 282240, while the sum is 49.

The spelling of 10921815778 in words is "ten billion, nine hundred twenty-one million, eight hundred fifteen thousand, seven hundred seventy-eight".