25809988 has 6 divisors (see below), whose sum is σ = 45167486. Its totient is φ = 12904992.

The previous prime is 25809983. The next prime is 25809997. The reversal of 25809988 is 88990852.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 20088324 + 5721664 = 4482^2 + 2392^2 .

It is not an unprimeable number, because it can be changed into a prime (25809983) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3226245 + ... + 3226252.

Almost surely, 2^25809988 is an apocalyptic number.

It is an amenable number.

25809988 is a deficient number, since it is larger than the sum of its proper divisors (19357498).

25809988 is a wasteful number, since it uses less digits than its factorization.

25809988 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6452501 (or 6452499 counting only the distinct ones).

The product of its (nonzero) digits is 414720, while the sum is 49.

The square root of 25809988 is about 5080.3531373321. The cubic root of 25809988 is about 295.5261623858.

The spelling of 25809988 in words is "twenty-five million, eight hundred nine thousand, nine hundred eighty-eight".