21221546642625 has 64 divisors (see below), whose sum is σ = 41180937408000. Its totient is φ = 9701278406400.

The previous prime is 21221546642617. The next prime is 21221546642627. The reversal of 21221546642625 is 52624664512212.

It is not a de Polignac number, because 21221546642625 - 2³ = 21221546642617 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21221546642627) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 82365240 + ... + 82622489.

It is an arithmetic number, because the mean of its divisors is an integer number (643452147000).

Almost surely, 2^{21221546642625} is an apocalyptic number.

21221546642625 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21221546642625 is a deficient number, since it is larger than the sum of its proper divisors (19959390765375).

21221546642625 is an equidigital number, since it uses as much as digits as its factorization.

21221546642625 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 164987768 (or 164987744 counting only the distinct ones).

The product of its digits is 2764800, while the sum is 48.

The spelling of 21221546642625 in words is "twenty-one trillion, two hundred twenty-one billion, five hundred forty-six million, six hundred forty-two thousand, six hundred twenty-five".