20665166356 has 12 divisors (see below), whose sum is σ = 36166965268. Its totient is φ = 10331747712.

The previous prime is 20665166321. The next prime is 20665166399. The reversal of 20665166356 is 65366156602.

It can be written as a sum of positive squares in 2 ways, for example, as 11424189456 + 9240976900 = 106884^2 + 96130^2 .

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 151461 + ... + 253516.

Almost surely, 2^20665166356 is an apocalyptic number.

It is an amenable number.

20665166356 is a deficient number, since it is larger than the sum of its proper divisors (15501798912).

20665166356 is a wasteful number, since it uses less digits than its factorization.

20665166356 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 417738 (or 417736 counting only the distinct ones).

The product of its (nonzero) digits is 1166400, while the sum is 46.

The spelling of 20665166356 in words is "twenty billion, six hundred sixty-five million, one hundred sixty-six thousand, three hundred fifty-six".