21455992529 has 2 divisors, whose sum is σ = 21455992530. Its totient is φ = 21455992528.

The previous prime is 21455992501. The next prime is 21455992559. The reversal of 21455992529 is 92529955412.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 13694382529 + 7761610000 = 117023^2 + 88100^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21455992529 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (21455992559) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10727996264 + 10727996265.

It is an arithmetic number, because the mean of its divisors is an integer number (10727996265).

Almost surely, 2^21455992529 is an apocalyptic number.

It is an amenable number.

21455992529 is a deficient number, since it is larger than the sum of its proper divisors (1).

21455992529 is an equidigital number, since it uses as much as digits as its factorization.

21455992529 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2916000, while the sum is 53.

The spelling of 21455992529 in words is "twenty-one billion, four hundred fifty-five million, nine hundred ninety-two thousand, five hundred twenty-nine".