25851989 has 4 divisors (see below), whose sum is σ = 27212640. Its totient is φ = 24491340.

The previous prime is 25851979. The next prime is 25851997. The reversal of 25851989 is 98915852.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 25851989 - 2⁸ = 25851733 is a prime.

It is a super-2 number, since 2×25851989² = 1336650670512242, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (25851929) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 680297 + ... + 680334.

It is an arithmetic number, because the mean of its divisors is an integer number (6803160).

Almost surely, 2^25851989 is an apocalyptic number.

It is an amenable number.

25851989 is a deficient number, since it is larger than the sum of its proper divisors (1360651).

25851989 is a wasteful number, since it uses less digits than its factorization.

25851989 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1360650.

The product of its digits is 259200, while the sum is 47.

The square root of 25851989 is about 5084.4851263427. The cubic root of 25851989 is about 295.6863803017.

The spelling of 25851989 in words is "twenty-five million, eight hundred fifty-one thousand, nine hundred eighty-nine".