25221765 has 16 divisors (see below), whose sum is σ = 41340096. Its totient is φ = 13123200.

The previous prime is 25221739. The next prime is 25221767. The reversal of 25221765 is 56712252.

It is not a de Polignac number, because 25221765 - 2⁹ = 25221253 is a prime.

It is a super-2 number, since 2×25221765² = 1272274859430450, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (25221767) 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, 19891 + ... + 21120.

It is an arithmetic number, because the mean of its divisors is an integer number (2583756).

Almost surely, 2^25221765 is an apocalyptic number.

It is an amenable number.

25221765 is a deficient number, since it is larger than the sum of its proper divisors (16118331).

25221765 is a wasteful number, since it uses less digits than its factorization.

25221765 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 41060.

The product of its digits is 8400, while the sum is 30.

The square root of 25221765 is about 5022.1275372097. The cubic root of 25221765 is about 293.2638229178.

The spelling of 25221765 in words is "twenty-five million, two hundred twenty-one thousand, seven hundred sixty-five".