25999981 has 8 divisors (see below), whose sum is σ = 30003584. Its totient is φ = 22068720.

The previous prime is 25999949. The next prime is 26000003. The reversal of 25999981 is 18999952.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 25999981 - 2⁵ = 25999949 is a prime.

It is a super-2 number, since 2×25999981² = 1351998024000722, 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 (25999081) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 17310 + ... + 18751.

It is an arithmetic number, because the mean of its divisors is an integer number (3750448).

Almost surely, 2^25999981 is an apocalyptic number.

It is an amenable number.

25999981 is a deficient number, since it is larger than the sum of its proper divisors (4003603).

25999981 is a wasteful number, since it uses less digits than its factorization.

25999981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 36171.

The product of its digits is 524880, while the sum is 52.

The square root of 25999981 is about 5099.0176504892. The cubic root of 25999981 is about 296.2495346774.

The spelling of 25999981 in words is "twenty-five million, nine hundred ninety-nine thousand, nine hundred eighty-one".