25217811979 has 2 divisors, whose sum is σ = 25217811980. Its totient is φ = 25217811978.

The previous prime is 25217811937. The next prime is 25217811991. The reversal of 25217811979 is 97911871252.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 25217811979 - 2¹⁹ = 25217287691 is a prime.

It is not a weakly prime, because it can be changed into another prime (25217812979) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12608905989 + 12608905990.

It is an arithmetic number, because the mean of its divisors is an integer number (12608905990).

Almost surely, 2^25217811979 is an apocalyptic number.

25217811979 is a deficient number, since it is larger than the sum of its proper divisors (1).

25217811979 is an equidigital number, since it uses as much as digits as its factorization.

25217811979 is an evil number, because the sum of its binary digits is even.

The product of its digits is 635040, while the sum is 52.

The spelling of 25217811979 in words is "twenty-five billion, two hundred seventeen million, eight hundred eleven thousand, nine hundred seventy-nine".