21221546642624 has 28 divisors (see below), whose sum is σ = 43007496127584. Its totient is φ = 10385012185344.

The previous prime is 21221546642617. The next prime is 21221546642627. The reversal of 21221546642624 is 42624664512212.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (47).

It is not an unprimeable number, because it can be changed into a prime (21221546642627) 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, 3527514719 + ... + 3527520734.

Almost surely, 2^{21221546642624} is an apocalyptic number.

It is an amenable number.

21221546642624 is an abundant number, since it is smaller than the sum of its proper divisors (21785949484960).

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

21221546642624 is an equidigital number, since it uses as much as digits as its factorization.

21221546642624 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7055035512 (or 7055035502 counting only the distinct ones).

The product of its digits is 2211840, while the sum is 47.

The spelling of 21221546642624 in words is "twenty-one trillion, two hundred twenty-one billion, five hundred forty-six million, six hundred forty-two thousand, six hundred twenty-four".