21751664626 has 16 divisors (see below), whose sum is σ = 34907765760. Its totient is φ = 10134510480.

The previous prime is 21751664617. The next prime is 21751664677. The reversal of 21751664626 is 62646615712.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4689586 + ... + 4694221.

It is an arithmetic number, because the mean of its divisors is an integer number (2181735360).

Almost surely, 2^21751664626 is an apocalyptic number.

21751664626 is a deficient number, since it is larger than the sum of its proper divisors (13156101134).

21751664626 is a wasteful number, since it uses less digits than its factorization.

21751664626 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9383889.

The product of its digits is 725760, while the sum is 46.

The spelling of 21751664626 in words is "twenty-one billion, seven hundred fifty-one million, six hundred sixty-four thousand, six hundred twenty-six".