21634964547 has 32 divisors (see below), whose sum is σ = 33221627904. Its totient is φ = 12267914400.

The previous prime is 21634964543. The next prime is 21634964591. The reversal of 21634964547 is 74546943612.

It is not a de Polignac number, because 21634964547 - 2² = 21634964543 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21634964547.

It is not an unprimeable number, because it can be changed into a prime (21634964543) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1530522 + ... + 1544592.

It is an arithmetic number, because the mean of its divisors is an integer number (1038175872).

Almost surely, 2^21634964547 is an apocalyptic number.

21634964547 is a deficient number, since it is larger than the sum of its proper divisors (11586663357).

21634964547 is a wasteful number, since it uses less digits than its factorization.

21634964547 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14639.

The product of its digits is 4354560, while the sum is 51.

The spelling of 21634964547 in words is "twenty-one billion, six hundred thirty-four million, nine hundred sixty-four thousand, five hundred forty-seven".