21665386622 has 12 divisors (see below), whose sum is σ = 35721030408. Its totient is φ = 9847902900.

The previous prime is 21665386621. The next prime is 21665386627. The reversal of 21665386622 is 22668356612.

It is a hoax number, since the sum of its digits (47) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21665386621) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 44762954 + ... + 44763437.

It is an arithmetic number, because the mean of its divisors is an integer number (2976752534).

Almost surely, 2^21665386622 is an apocalyptic number.

21665386622 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

21665386622 is a deficient number, since it is larger than the sum of its proper divisors (14055643786).

21665386622 is a wasteful number, since it uses less digits than its factorization.

21665386622 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 89526415 (or 89526404 counting only the distinct ones).

The product of its digits is 1244160, while the sum is 47.

The spelling of 21665386622 in words is "twenty-one billion, six hundred sixty-five million, three hundred eighty-six thousand, six hundred twenty-two".