25981605 has 48 divisors (see below), whose sum is σ = 50633856. Its totient is φ = 12228480.

The previous prime is 25981603. The next prime is 25981609. The reversal of 25981605 is 50618952.

It is a happy number.

25981605 is a `hidden beast` number, since 2 + 598 + 1 + 60 + 5 = 666.

It is not a de Polignac number, because 25981605 - 2¹ = 25981603 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 25981605.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (25981601) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 12490 + ... + 14420.

It is an arithmetic number, because the mean of its divisors is an integer number (1054872).

Almost surely, 2^25981605 is an apocalyptic number.

It is an amenable number.

25981605 is a deficient number, since it is larger than the sum of its proper divisors (24652251).

25981605 is a wasteful number, since it uses less digits than its factorization.

25981605 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1978 (or 1975 counting only the distinct ones).

The product of its (nonzero) digits is 21600, while the sum is 36.

The square root of 25981605 is about 5097.2154162837. The cubic root of 25981605 is about 296.1797248254.

The spelling of 25981605 in words is "twenty-five million, nine hundred eighty-one thousand, six hundred five".