20856147866 has 8 divisors (see below), whose sum is σ = 31287280404. Its totient is φ = 10427054400.

The previous prime is 20856147857. The next prime is 20856147883. The reversal of 20856147866 is 66874165802.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 20770862641 + 85285225 = 144121^2 + 9235^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 483935 + ... + 525266.

Almost surely, 2^20856147866 is an apocalyptic number.

20856147866 is a deficient number, since it is larger than the sum of its proper divisors (10431132538).

20856147866 is a wasteful number, since it uses less digits than its factorization.

20856147866 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1019536.

The product of its (nonzero) digits is 3870720, while the sum is 53.

The spelling of 20856147866 in words is "twenty billion, eight hundred fifty-six million, one hundred forty-seven thousand, eight hundred sixty-six".