25669640 has 32 divisors (see below), whose sum is σ = 59751000. Its totient is φ = 9913344.

The previous prime is 25669619. The next prime is 25669673. The reversal of 25669640 is 4696652.

It can be written as a sum of positive squares in 4 ways, for example, as 25020004 + 649636 = 5002^2 + 806^2 .

It is a Smith number, since the sum of its digits (38) coincides with the sum of the digits of its prime factors.

It is a junction number, because it is equal to n+sod(n) for n = 25669594 and 25669603.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 9905 + ... + 12224.

Almost surely, 2^25669640 is an apocalyptic number.

25669640 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

25669640 is an abundant number, since it is smaller than the sum of its proper divisors (34081360).

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

25669640 is a wasteful number, since it uses less digits than its factorization.

25669640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22169 (or 22165 counting only the distinct ones).

The product of its (nonzero) digits is 77760, while the sum is 38.

The square root of 25669640 is about 5066.5214891482. The cubic root of 25669640 is about 294.9895237111.

It can be divided in two parts, 256 and 69640, that added together give a palindrome (69896).

The spelling of 25669640 in words is "twenty-five million, six hundred sixty-nine thousand, six hundred forty".