21952355649 has 32 divisors (see below), whose sum is σ = 34625760000. Its totient is φ = 12104273664.

The previous prime is 21952355639. The next prime is 21952355653. The reversal of 21952355649 is 94655325912.

It is not a de Polignac number, because 21952355649 - 2⁷ = 21952355521 is a prime.

It is a super-2 number, since 2×21952355649² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21952355639) 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 31 ways as a sum of consecutive naturals, for example, 1079427 + ... + 1099575.

It is an arithmetic number, because the mean of its divisors is an integer number (1082055000).

Almost surely, 2^21952355649 is an apocalyptic number.

21952355649 is a gapful number since it is divisible by the number (29) formed by its first and last digit.

It is an amenable number.

21952355649 is a deficient number, since it is larger than the sum of its proper divisors (12673404351).

21952355649 is a wasteful number, since it uses less digits than its factorization.

21952355649 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21977.

The product of its digits is 2916000, while the sum is 51.

The spelling of 21952355649 in words is "twenty-one billion, nine hundred fifty-two million, three hundred fifty-five thousand, six hundred forty-nine".