20215666888 has 8 divisors (see below), whose sum is σ = 37904375430. Its totient is φ = 10107833440.

The previous prime is 20215666879. The next prime is 20215666901. The reversal of 20215666888 is 88866651202.

It can be written as a sum of positive squares in only one way, i.e., 14131978884 + 6083688004 = 118878^2 + 77998^2 .

It is a tau number, because it is divible by the number of its divisors (8).

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1263479173 + ... + 1263479188.

Almost surely, 2^20215666888 is an apocalyptic number.

It is an amenable number.

20215666888 is a deficient number, since it is larger than the sum of its proper divisors (17688708542).

20215666888 is a wasteful number, since it uses less digits than its factorization.

20215666888 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2526958367 (or 2526958363 counting only the distinct ones).

The product of its (nonzero) digits is 2211840, while the sum is 52.

The spelling of 20215666888 in words is "twenty billion, two hundred fifteen million, six hundred sixty-six thousand, eight hundred eighty-eight".