25981813 has 16 divisors (see below), whose sum is σ = 31514112. Its totient is φ = 21096000.

The previous prime is 25981801. The next prime is 25981841. The reversal of 25981813 is 31818952.

It is a cyclic number.

It is not a de Polignac number, because 25981813 - 2¹³ = 25973621 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (25981843) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1503 + ... + 7363.

It is an arithmetic number, because the mean of its divisors is an integer number (1969632).

Almost surely, 2^25981813 is an apocalyptic number.

It is an amenable number.

25981813 is a deficient number, since it is larger than the sum of its proper divisors (5532299).

25981813 is a wasteful number, since it uses less digits than its factorization.

25981813 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5916.

The product of its digits is 17280, while the sum is 37.

The square root of 25981813 is about 5097.2358195398. The cubic root of 25981813 is about 296.1805151950.

It can be divided in two parts, 2598 and 1813, that multiplied together give a palindrome (4710174).

The spelling of 25981813 in words is "twenty-five million, nine hundred eighty-one thousand, eight hundred thirteen".