20259442921 has 2 divisors, whose sum is σ = 20259442922. Its totient is φ = 20259442920.

The previous prime is 20259442897. The next prime is 20259442937. The reversal of 20259442921 is 12924495202.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 19709071321 + 550371600 = 140389^2 + 23460^2 .

It is a cyclic number.

It is not a de Polignac number, because 20259442921 - 2²⁵ = 20225888489 is a prime.

It is not a weakly prime, because it can be changed into another prime (20259442321) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10129721460 + 10129721461.

It is an arithmetic number, because the mean of its divisors is an integer number (10129721461).

Almost surely, 2^20259442921 is an apocalyptic number.

It is an amenable number.

20259442921 is a deficient number, since it is larger than the sum of its proper divisors (1).

20259442921 is an equidigital number, since it uses as much as digits as its factorization.

20259442921 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 103680, while the sum is 40.

The spelling of 20259442921 in words is "twenty billion, two hundred fifty-nine million, four hundred forty-two thousand, nine hundred twenty-one".