25531391 has 4 divisors (see below), whose sum is σ = 25663872. Its totient is φ = 25398912.

The previous prime is 25531361. The next prime is 25531409. The reversal of 25531391 is 19313552.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 25531391 - 2⁶ = 25531327 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (25531301) 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, 65951 + ... + 66336.

It is an arithmetic number, because the mean of its divisors is an integer number (6415968).

Almost surely, 2^25531391 is an apocalyptic number.

25531391 is a deficient number, since it is larger than the sum of its proper divisors (132481).

25531391 is a wasteful number, since it uses less digits than its factorization.

25531391 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 132480.

The product of its digits is 4050, while the sum is 29.

The square root of 25531391 is about 5052.8596853663. The cubic root of 25531391 is about 294.4589950432.

The spelling of 25531391 in words is "twenty-five million, five hundred thirty-one thousand, three hundred ninety-one".