25221423173 has 2 divisors, whose sum is σ = 25221423174. Its totient is φ = 25221423172.

The previous prime is 25221423167. The next prime is 25221423263. The reversal of 25221423173 is 37132412252.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 15016786849 + 10204636324 = 122543^2 + 101018^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-25221423173 is a prime.

It is a super-2 number, since 2×25221423173² (a number of 22 digits) contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (25221423103) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12610711586 + 12610711587.

It is an arithmetic number, because the mean of its divisors is an integer number (12610711587).

Almost surely, 2^25221423173 is an apocalyptic number.

It is an amenable number.

25221423173 is a deficient number, since it is larger than the sum of its proper divisors (1).

25221423173 is an equidigital number, since it uses as much as digits as its factorization.

25221423173 is an evil number, because the sum of its binary digits is even.

The product of its digits is 20160, while the sum is 32.

The spelling of 25221423173 in words is "twenty-five billion, two hundred twenty-one million, four hundred twenty-three thousand, one hundred seventy-three".