21958115929 has 2 divisors, whose sum is σ = 21958115930. Its totient is φ = 21958115928.

The previous prime is 21958115903. The next prime is 21958115983. The reversal of 21958115929 is 92951185912.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 19111680025 + 2846435904 = 138245^2 + 53352^2 .

It is a cyclic number.

It is not a de Polignac number, because 21958115929 - 2⁵ = 21958115897 is a prime.

It is not a weakly prime, because it can be changed into another prime (21958115999) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10979057964 + 10979057965.

It is an arithmetic number, because the mean of its divisors is an integer number (10979057965).

Almost surely, 2^21958115929 is an apocalyptic number.

It is an amenable number.

21958115929 is a deficient number, since it is larger than the sum of its proper divisors (1).

21958115929 is an equidigital number, since it uses as much as digits as its factorization.

21958115929 is an evil number, because the sum of its binary digits is even.

The product of its digits is 583200, while the sum is 52.

The spelling of 21958115929 in words is "twenty-one billion, nine hundred fifty-eight million, one hundred fifteen thousand, nine hundred twenty-nine".