25491397 has 2 divisors, whose sum is σ = 25491398. Its totient is φ = 25491396.

The previous prime is 25491371. The next prime is 25491439. The reversal of 25491397 is 79319452.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 24344356 + 1147041 = 4934^2 + 1071^2 .

It is a cyclic number.

It is not a de Polignac number, because 25491397 - 2¹¹ = 25489349 is a prime.

It is a super-2 number, since 2×25491397² = 1299622642023218, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (25491317) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12745698 + 12745699.

It is an arithmetic number, because the mean of its divisors is an integer number (12745699).

Almost surely, 2^25491397 is an apocalyptic number.

It is an amenable number.

25491397 is a deficient number, since it is larger than the sum of its proper divisors (1).

25491397 is an equidigital number, since it uses as much as digits as its factorization.

25491397 is an evil number, because the sum of its binary digits is even.

The product of its digits is 68040, while the sum is 40.

The square root of 25491397 is about 5048.9005733922. The cubic root of 25491397 is about 294.3051615707.

The spelling of 25491397 in words is "twenty-five million, four hundred ninety-one thousand, three hundred ninety-seven".