21577863020818 has 16 divisors (see below), whose sum is σ = 35667165352896. Its totient is φ = 9727408731600.

The previous prime is 21577863020803. The next prime is 21577863020839. The reversal of 21577863020818 is 81802036877512.

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, 9650205958 + ... + 9650208193.

It is an arithmetic number, because the mean of its divisors is an integer number (2229197834556).

Almost surely, 2^{21577863020818} is an apocalyptic number.

21577863020818 is a deficient number, since it is larger than the sum of its proper divisors (14089302332078).

21577863020818 is a wasteful number, since it uses less digits than its factorization.

21577863020818 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19300414209.

The product of its (nonzero) digits is 9031680, while the sum is 58.

The spelling of 21577863020818 in words is "twenty-one trillion, five hundred seventy-seven billion, eight hundred sixty-three million, twenty thousand, eight hundred eighteen".