25685981 has 8 divisors (see below), whose sum is σ = 26113920. Its totient is φ = 25260768.

The previous prime is 25685977. The next prime is 25685983. The reversal of 25685981 is 18958652.

25685981 = T₁₉₈ + T₁₉₉ + ... + T₅₄₄.

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 25685981 - 2² = 25685977 is a prime.

It is a super-2 number, since 2×25685981² = 1319539239864722, 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 (25685983) 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, 26945 + ... + 27881.

It is an arithmetic number, because the mean of its divisors is an integer number (3264240).

Almost surely, 2^25685981 is an apocalyptic number.

It is an amenable number.

25685981 is a deficient number, since it is larger than the sum of its proper divisors (427939).

25685981 is an equidigital number, since it uses as much as digits as its factorization.

25685981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1363.

The product of its digits is 172800, while the sum is 44.

The square root of 25685981 is about 5068.1338774740. The cubic root of 25685981 is about 295.0521060885.

The spelling of 25685981 in words is "twenty-five million, six hundred eighty-five thousand, nine hundred eighty-one".