21486305643856 has 40 divisors (see below), whose sum is σ = 42646696311744. Its totient is φ = 10480726506240.

The previous prime is 21486305643821. The next prime is 21486305643899. The reversal of 21486305643856 is 65834650368412.

It is a super-2 number, since 2×21486305643856² (a number of 27 digits) contains 22 as substring.

It is a Smith number, since the sum of its digits (61) coincides with the sum of the digits of its prime factors.

It is a junction number, because it is equal to n+sod(n) for n = 21486305643794 and 21486305643803.

It is a congruent number.

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, 17039635 + ... + 18257101.

Almost surely, 2^{21486305643856} is an apocalyptic number.

It is an amenable number.

21486305643856 is a deficient number, since it is larger than the sum of its proper divisors (21160390667888).

21486305643856 is a wasteful number, since it uses less digits than its factorization.

21486305643856 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1244419 (or 1244413 counting only the distinct ones).

The product of its (nonzero) digits is 99532800, while the sum is 61.

The spelling of 21486305643856 in words is "twenty-one trillion, four hundred eighty-six billion, three hundred five million, six hundred forty-three thousand, eight hundred fifty-six".