25394721 has 16 divisors (see below), whose sum is σ = 37566720. Its totient is φ = 15128720.

The previous prime is 25394713. The next prime is 25394723. The reversal of 25394721 is 12749352.

It is a cyclic number.

It is not a de Polignac number, because 25394721 - 2³ = 25394713 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is not an unprimeable number, because it can be changed into a prime (25394723) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4575 + ... + 8468.

It is an arithmetic number, because the mean of its divisors is an integer number (2347920).

Almost surely, 2^25394721 is an apocalyptic number.

It is an amenable number.

25394721 is a deficient number, since it is larger than the sum of its proper divisors (12171999).

25394721 is a wasteful number, since it uses less digits than its factorization.

25394721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13116.

The product of its digits is 15120, while the sum is 33.

The square root of 25394721 is about 5039.3175133147. The cubic root of 25394721 is about 293.9326399430.

It can be divided in two parts, 2539 and 4721, that added together give a triangular number (7260 = T₁₂₀).

The spelling of 25394721 in words is "twenty-five million, three hundred ninety-four thousand, seven hundred twenty-one".