25661331 has 12 divisors (see below), whose sum is σ = 37138920. Its totient is φ = 17074080.

The previous prime is 25661327. The next prime is 25661341. The reversal of 25661331 is 13316652.

It is not a de Polignac number, because 25661331 - 2² = 25661327 is a prime.

It is a super-2 number, since 2×25661331² = 1317007817383122, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 25661295 and 25661304.

It is not an unprimeable number, because it can be changed into a prime (25661341) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2616 + ... + 7626.

It is an arithmetic number, because the mean of its divisors is an integer number (3094910).

Almost surely, 2^25661331 is an apocalyptic number.

25661331 is a deficient number, since it is larger than the sum of its proper divisors (11477589).

25661331 is a wasteful number, since it uses less digits than its factorization.

25661331 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5586 (or 5583 counting only the distinct ones).

The product of its digits is 3240, while the sum is 27.

The square root of 25661331 is about 5065.7014321809. The cubic root of 25661331 is about 294.9576919121.

Adding to 25661331 its reverse (13316652), we get a palindrome (38977983).

The spelling of 25661331 in words is "twenty-five million, six hundred sixty-one thousand, three hundred thirty-one".