25776991 has 2 divisors, whose sum is σ = 25776992. Its totient is φ = 25776990.

The previous prime is 25776967. The next prime is 25777007. The reversal of 25776991 is 19967752.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-25776991 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (25776941) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12888495 + 12888496.

It is an arithmetic number, because the mean of its divisors is an integer number (12888496).

Almost surely, 2^25776991 is an apocalyptic number.

25776991 is a deficient number, since it is larger than the sum of its proper divisors (1).

25776991 is an equidigital number, since it uses as much as digits as its factorization.

25776991 is an evil number, because the sum of its binary digits is even.

The product of its digits is 238140, while the sum is 46.

The square root of 25776991 is about 5077.1045882471. The cubic root of 25776991 is about 295.4001693612.

The spelling of 25776991 in words is "twenty-five million, seven hundred seventy-six thousand, nine hundred ninety-one".