25130809721 has 2 divisors, whose sum is σ = 25130809722. Its totient is φ = 25130809720.

The previous prime is 25130809687. The next prime is 25130809747. The reversal of 25130809721 is 12790803152.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 14869119721 + 10261690000 = 121939^2 + 101300^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-25130809721 is a prime.

It is not a weakly prime, because it can be changed into another prime (25130809321) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12565404860 + 12565404861.

It is an arithmetic number, because the mean of its divisors is an integer number (12565404861).

Almost surely, 2^25130809721 is an apocalyptic number.

It is an amenable number.

25130809721 is a deficient number, since it is larger than the sum of its proper divisors (1).

25130809721 is an equidigital number, since it uses as much as digits as its factorization.

25130809721 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 30240, while the sum is 38.

The spelling of 25130809721 in words is "twenty-five billion, one hundred thirty million, eight hundred nine thousand, seven hundred twenty-one".