21616927647 has 16 divisors (see below), whose sum is σ = 33130490880. Its totient is φ = 12281126112.

The previous prime is 21616927573. The next prime is 21616927649. The reversal of 21616927647 is 74672961612.

It is a happy number.

It is not a de Polignac number, because 21616927647 - 2⁸ = 21616927391 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21616927647.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21616927649) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2971447 + ... + 2978712.

It is an arithmetic number, because the mean of its divisors is an integer number (2070655680).

Almost surely, 2^21616927647 is an apocalyptic number.

21616927647 is a deficient number, since it is larger than the sum of its proper divisors (11513563233).

21616927647 is a wasteful number, since it uses less digits than its factorization.

21616927647 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5950342.

The product of its digits is 1524096, while the sum is 51.

The spelling of 21616927647 in words is "twenty-one billion, six hundred sixteen million, nine hundred twenty-seven thousand, six hundred forty-seven".