21955237929 has 9 divisors (see below), whose sum is σ = 31713763549. Its totient is φ = 14636528940.

The previous prime is 21955237883. The next prime is 21955237939. The reversal of 21955237929 is 92973255912.

The square root of 21955237929 is 148173.

It is a perfect power (a square), and thus also a powerful number.

21955237929 is a `hidden beast` number, since 2 + 1 + 95 + 523 + 7 + 9 + 29 = 666.

It is a tau number, because it is divible by the number of its divisors (9).

It is not a de Polignac number, because 21955237929 - 2¹⁵ = 21955205161 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21955237939) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 419824 + ... + 469214.

Almost surely, 2^21955237929 is an apocalyptic number.

21955237929 is the 148173-rd square number.

21955237929 is the 74087-th centered octagonal number.

It is an amenable number.

21955237929 is a deficient number, since it is larger than the sum of its proper divisors (9758525620).

21955237929 is an frugal number, since it uses more digits than its factorization.

21955237929 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 98788 (or 49394 counting only the distinct ones).

The product of its digits is 3061800, while the sum is 54.

The spelling of 21955237929 in words is "twenty-one billion, nine hundred fifty-five million, two hundred thirty-seven thousand, nine hundred twenty-nine".