25616591 has 32 divisors (see below), whose sum is σ = 34825728. Its totient is φ = 18195840.

The previous prime is 25616573. The next prime is 25616597. The reversal of 25616591 is 19561652.

It is not a de Polignac number, because 25616591 - 2¹⁰ = 25615567 is a prime.

It is a super-2 number, since 2×25616591² = 1312419468922562, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (25616597) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 157076 + ... + 157238.

It is an arithmetic number, because the mean of its divisors is an integer number (1088304).

Almost surely, 2^25616591 is an apocalyptic number.

25616591 is a deficient number, since it is larger than the sum of its proper divisors (9209137).

25616591 is a wasteful number, since it uses less digits than its factorization.

25616591 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 351.

The product of its digits is 16200, while the sum is 35.

The square root of 25616591 is about 5061.2835328600. The cubic root of 25616591 is about 294.7861746488.

It can be divided in two parts, 25 and 616591, that added together give a palindrome (616616).

The spelling of 25616591 in words is "twenty-five million, six hundred sixteen thousand, five hundred ninety-one".