25091531 has 4 divisors (see below), whose sum is σ = 25340064. Its totient is φ = 24843000.

The previous prime is 25091509. The next prime is 25091543. The reversal of 25091531 is 13519052.

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 25091531 - 2¹⁴ = 25075147 is a prime.

It is a super-2 number, since 2×25091531² = 1259169855847922, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 25091531.

It is not an unprimeable number, because it can be changed into a prime (25091831) 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, 124115 + ... + 124316.

It is an arithmetic number, because the mean of its divisors is an integer number (6335016).

Almost surely, 2^25091531 is an apocalyptic number.

25091531 is a deficient number, since it is larger than the sum of its proper divisors (248533).

25091531 is a wasteful number, since it uses less digits than its factorization.

25091531 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 248532.

The product of its (nonzero) digits is 1350, while the sum is 26.

The square root of 25091531 is about 5009.1447373778. The cubic root of 25091531 is about 292.7581902227.

The spelling of 25091531 in words is "twenty-five million, ninety-one thousand, five hundred thirty-one".