21654599953 has 16 divisors (see below), whose sum is σ = 26055771520. Its totient is φ = 17580727296.

The previous prime is 21654599951. The next prime is 21654599957. The reversal of 21654599953 is 35999545612.

It is a cyclic number.

It is not a de Polignac number, because 21654599953 - 2¹ = 21654599951 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21654599951) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 829975 + ... + 855667.

It is an arithmetic number, because the mean of its divisors is an integer number (1628485720).

Almost surely, 2^21654599953 is an apocalyptic number.

It is an amenable number.

21654599953 is a deficient number, since it is larger than the sum of its proper divisors (4401171567).

21654599953 is a wasteful number, since it uses less digits than its factorization.

21654599953 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 32056.

The product of its digits is 13122000, while the sum is 58.

The spelling of 21654599953 in words is "twenty-one billion, six hundred fifty-four million, five hundred ninety-nine thousand, nine hundred fifty-three".