20856865802 has 8 divisors (see below), whose sum is σ = 31385252676. Its totient is φ = 10395114912.

The previous prime is 20856865709. The next prime is 20856865807.

20856865802 is nontrivially palindromic in base 10.

It can be written as a sum of positive squares in 2 ways, for example, as 19201922041 + 1654943761 = 138571^2 + 40681^2 .

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

It is not an unprimeable number, because it can be changed into a prime (20856865807) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 16658213 + ... + 16659464.

Almost surely, 2^20856865802 is an apocalyptic number.

20856865802 is a deficient number, since it is larger than the sum of its proper divisors (10528386874).

20856865802 is a wasteful number, since it uses less digits than its factorization.

20856865802 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 33317992.

The product of its (nonzero) digits is 1843200, while the sum is 50.

The spelling of 20856865802 in words is "twenty billion, eight hundred fifty-six million, eight hundred sixty-five thousand, eight hundred two".