21221854212736 has 64 divisors (see below), whose sum is σ = 43030405440000. Its totient is φ = 10423429825536.

The previous prime is 21221854212679. The next prime is 21221854212799. The reversal of 21221854212736 is 63721245812212.

It is a tau number, because it is divible by the number of its divisors (64).

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, 3334536 + ... + 7318663.

It is an arithmetic number, because the mean of its divisors is an integer number (672350085000).

Almost surely, 2^{21221854212736} is an apocalyptic number.

It is an amenable number.

21221854212736 is an abundant number, since it is smaller than the sum of its proper divisors (21808551227264).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21221854212736 is a wasteful number, since it uses less digits than its factorization.

21221854212736 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10653489 (or 10653477 counting only the distinct ones).

The product of its digits is 645120, while the sum is 46.

The spelling of 21221854212736 in words is "twenty-one trillion, two hundred twenty-one billion, eight hundred fifty-four million, two hundred twelve thousand, seven hundred thirty-six".