25431861 has 32 divisors (see below), whose sum is σ = 43939840. Its totient is φ = 12705984.

The previous prime is 25431853. The next prime is 25431863. The reversal of 25431861 is 16813452.

It is not a de Polignac number, because 25431861 - 2³ = 25431853 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (25431863) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 2736 + ... + 7638.

It is an arithmetic number, because the mean of its divisors is an integer number (1373120).

Almost surely, 2^25431861 is an apocalyptic number.

25431861 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

25431861 is a deficient number, since it is larger than the sum of its proper divisors (18507979).

25431861 is a wasteful number, since it uses less digits than its factorization.

25431861 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4945.

The product of its digits is 5760, while the sum is 30.

The square root of 25431861 is about 5043.0011897679. The cubic root of 25431861 is about 294.0758631568.

The spelling of 25431861 in words is "twenty-five million, four hundred thirty-one thousand, eight hundred sixty-one".