25420565173 has 2 divisors, whose sum is σ = 25420565174. Its totient is φ = 25420565172.

The previous prime is 25420565143. The next prime is 25420565201. The reversal of 25420565173 is 37156502452.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 23451247044 + 1969318129 = 153138^2 + 44377^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-25420565173 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (25420565123) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12710282586 + 12710282587.

It is an arithmetic number, because the mean of its divisors is an integer number (12710282587).

Almost surely, 2^25420565173 is an apocalyptic number.

It is an amenable number.

25420565173 is a deficient number, since it is larger than the sum of its proper divisors (1).

25420565173 is an equidigital number, since it uses as much as digits as its factorization.

25420565173 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 252000, while the sum is 40.

The spelling of 25420565173 in words is "twenty-five billion, four hundred twenty million, five hundred sixty-five thousand, one hundred seventy-three".