25195981 has 2 divisors, whose sum is σ = 25195982. Its totient is φ = 25195980.

The previous prime is 25195969. The next prime is 25195991. The reversal of 25195981 is 18959152.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 14891881 + 10304100 = 3859^2 + 3210^2 .

It is a cyclic number.

It is not a de Polignac number, because 25195981 - 2¹⁷ = 25064909 is a prime.

It is a super-2 number, since 2×25195981² = 1269674917104722, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (25195991) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12597990 + 12597991.

It is an arithmetic number, because the mean of its divisors is an integer number (12597991).

Almost surely, 2^25195981 is an apocalyptic number.

It is an amenable number.

25195981 is a deficient number, since it is larger than the sum of its proper divisors (1).

25195981 is an equidigital number, since it uses as much as digits as its factorization.

25195981 is an evil number, because the sum of its binary digits is even.

The product of its digits is 32400, while the sum is 40.

The square root of 25195981 is about 5019.5598412610. The cubic root of 25195981 is about 293.1638551246.

The spelling of 25195981 in words is "twenty-five million, one hundred ninety-five thousand, nine hundred eighty-one".