21646898949 has 96 divisors (see below), whose sum is σ = 35025177600. Its totient is φ = 11778545664.

The previous prime is 21646898849. The next prime is 21646898957. The reversal of 21646898949 is 94989864612.

It is not a de Polignac number, because 21646898949 - 2⁹ = 21646898437 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21646898949.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21646898989) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 35661804 + ... + 35662410.

It is an arithmetic number, because the mean of its divisors is an integer number (364845600).

Almost surely, 2^21646898949 is an apocalyptic number.

It is an amenable number.

21646898949 is a deficient number, since it is larger than the sum of its proper divisors (13378278651).

21646898949 is a wasteful number, since it uses less digits than its factorization.

21646898949 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 827 (or 808 counting only the distinct ones).

The product of its digits is 53747712, while the sum is 66.

The spelling of 21646898949 in words is "twenty-one billion, six hundred forty-six million, eight hundred ninety-eight thousand, nine hundred forty-nine".