21958115923 has 16 divisors (see below), whose sum is σ = 22683276000. Its totient is φ = 21242373120.

The previous prime is 21958115903. The next prime is 21958115929. The reversal of 21958115923 is 32951185912.

It is a cyclic number.

It is not a de Polignac number, because 21958115923 - 2⁹ = 21958115411 is a prime.

It is a super-2 number, since 2×21958115923² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21958115929) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 5976415 + ... + 5980087.

It is an arithmetic number, because the mean of its divisors is an integer number (1417704750).

Almost surely, 2^21958115923 is an apocalyptic number.

21958115923 is a deficient number, since it is larger than the sum of its proper divisors (725160077).

21958115923 is a wasteful number, since it uses less digits than its factorization.

21958115923 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4902.

The product of its digits is 194400, while the sum is 46.

It can be divided in two parts, 2195 and 8115923, that added together give a palindrome (8118118).

The spelling of 21958115923 in words is "twenty-one billion, nine hundred fifty-eight million, one hundred fifteen thousand, nine hundred twenty-three".