25516991 has 2 divisors, whose sum is σ = 25516992. Its totient is φ = 25516990.

The previous prime is 25516979. The next prime is 25517021. The reversal of 25516991 is 19961552.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 25516991 - 2⁶ = 25516927 is a prime.

It is a super-2 number, since 2×25516991² = 1302233659388162, 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 (25516951) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12758495 + 12758496.

It is an arithmetic number, because the mean of its divisors is an integer number (12758496).

Almost surely, 2^25516991 is an apocalyptic number.

25516991 is a deficient number, since it is larger than the sum of its proper divisors (1).

25516991 is an equidigital number, since it uses as much as digits as its factorization.

25516991 is an evil number, because the sum of its binary digits is even.

The product of its digits is 24300, while the sum is 38.

The square root of 25516991 is about 5051.4345487198. The cubic root of 25516991 is about 294.4036252052.

The spelling of 25516991 in words is "twenty-five million, five hundred sixteen thousand, nine hundred ninety-one".