25162665491 has 2 divisors, whose sum is σ = 25162665492. Its totient is φ = 25162665490.

The previous prime is 25162665419. The next prime is 25162665527. The reversal of 25162665491 is 19456626152.

Together with previous prime (25162665419) it forms an Ormiston pair, because they use the same digits, order apart.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 25162665491 - 2¹⁰ = 25162664467 is a prime.

It is a super-2 number, since 2×25162665491² (a number of 22 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (25162665391) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12581332745 + 12581332746.

It is an arithmetic number, because the mean of its divisors is an integer number (12581332746).

Almost surely, 2^25162665491 is an apocalyptic number.

25162665491 is a deficient number, since it is larger than the sum of its proper divisors (1).

25162665491 is an equidigital number, since it uses as much as digits as its factorization.

25162665491 is an evil number, because the sum of its binary digits is even.

The product of its digits is 777600, while the sum is 47.

The spelling of 25162665491 in words is "twenty-five billion, one hundred sixty-two million, six hundred sixty-five thousand, four hundred ninety-one".