25640478 has 12 divisors (see below), whose sum is σ = 55554408. Its totient is φ = 8546820.

The previous prime is 25640467. The next prime is 25640479. The reversal of 25640478 is 87404652.

25640478 is a `hidden beast` number, since 2 + 5 + 640 + 4 + 7 + 8 = 666.

It is a super-2 number, since 2×25640478² = 1314868224136968, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (25640479) 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, 712218 + ... + 712253.

It is an arithmetic number, because the mean of its divisors is an integer number (4629534).

Almost surely, 2^25640478 is an apocalyptic number.

25640478 is an abundant number, since it is smaller than the sum of its proper divisors (29913930).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

25640478 is a wasteful number, since it uses less digits than its factorization.

25640478 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1424479 (or 1424476 counting only the distinct ones).

The product of its (nonzero) digits is 53760, while the sum is 36.

The square root of 25640478 is about 5063.6427599111. The cubic root of 25640478 is about 294.8777737454.

The spelling of 25640478 in words is "twenty-five million, six hundred forty thousand, four hundred seventy-eight".