21997504159 has 2 divisors, whose sum is σ = 21997504160. Its totient is φ = 21997504158.

The previous prime is 21997504073. The next prime is 21997504169. The reversal of 21997504159 is 95140579912.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21997504159 - 2²⁵ = 21963949727 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21997504169) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10998752079 + 10998752080.

It is an arithmetic number, because the mean of its divisors is an integer number (10998752080).

Almost surely, 2^21997504159 is an apocalyptic number.

21997504159 is a deficient number, since it is larger than the sum of its proper divisors (1).

21997504159 is an equidigital number, since it uses as much as digits as its factorization.

21997504159 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1020600, while the sum is 52.

The spelling of 21997504159 in words is "twenty-one billion, nine hundred ninety-seven million, five hundred four thousand, one hundred fifty-nine".