25172561 has 2 divisors, whose sum is σ = 25172562. Its totient is φ = 25172560.

The previous prime is 25172491. The next prime is 25172573. The reversal of 25172561 is 16527152.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 19140625 + 6031936 = 4375^2 + 2456^2 .

It is a cyclic number.

It is not a de Polignac number, because 25172561 - 2²² = 20978257 is a prime.

It is not a weakly prime, because it can be changed into another prime (25175561) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12586280 + 12586281.

It is an arithmetic number, because the mean of its divisors is an integer number (12586281).

Almost surely, 2^25172561 is an apocalyptic number.

It is an amenable number.

25172561 is a deficient number, since it is larger than the sum of its proper divisors (1).

25172561 is an equidigital number, since it uses as much as digits as its factorization.

25172561 is an evil number, because the sum of its binary digits is even.

The product of its digits is 4200, while the sum is 29.

The square root of 25172561 is about 5017.2264250281. The cubic root of 25172561 is about 293.0729937302.

The spelling of 25172561 in words is "twenty-five million, one hundred seventy-two thousand, five hundred sixty-one".