25649491 has 6 divisors (see below), whose sum is σ = 29837220. Its totient is φ = 21985236.

The previous prime is 25649467. The next prime is 25649501. The reversal of 25649491 is 19494652.

It is not a de Polignac number, because 25649491 - 2²³ = 17260883 is a prime.

It is a super-3 number, since 3×25649491³ (a number of 23 digits) contains 333 as substring.

It is not an unprimeable number, because it can be changed into a prime (25649401) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 261681 + ... + 261778.

It is an arithmetic number, because the mean of its divisors is an integer number (4972870).

Almost surely, 2^25649491 is an apocalyptic number.

25649491 is a deficient number, since it is larger than the sum of its proper divisors (4187729).

25649491 is an equidigital number, since it uses as much as digits as its factorization.

25649491 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 523473 (or 523466 counting only the distinct ones).

The product of its digits is 77760, while the sum is 40.

The square root of 25649491 is about 5064.5326536611. The cubic root of 25649491 is about 294.9123209696.

The spelling of 25649491 in words is "twenty-five million, six hundred forty-nine thousand, four hundred ninety-one".