25661481 has 4 divisors (see below), whose sum is σ = 34215312. Its totient is φ = 17107652.

The previous prime is 25661479. The next prime is 25661501. The reversal of 25661481 is 18416652.

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 25661481 - 2¹ = 25661479 is a prime.

It is a super-2 number, since 2×25661481² = 1317023214226722, which contains 22 as substring.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (25661081) 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, 4276911 + ... + 4276916.

It is an arithmetic number, because the mean of its divisors is an integer number (8553828).

Almost surely, 2^25661481 is an apocalyptic number.

It is an amenable number.

25661481 is a deficient number, since it is larger than the sum of its proper divisors (8553831).

25661481 is an equidigital number, since it uses as much as digits as its factorization.

25661481 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8553830.

The product of its digits is 11520, while the sum is 33.

The square root of 25661481 is about 5065.7162376114. The cubic root of 25661481 is about 294.9582666233.

The spelling of 25661481 in words is "twenty-five million, six hundred sixty-one thousand, four hundred eighty-one".