25661145 has 16 divisors (see below), whose sum is σ = 41120640. Its totient is φ = 13665024.

The previous prime is 25661137. The next prime is 25661147. The reversal of 25661145 is 54116652.

It is not a de Polignac number, because 25661145 - 2³ = 25661137 is a prime.

It is a super-2 number, since 2×25661145² = 1316988725422050, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (25661147) 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, 18796 + ... + 20114.

It is an arithmetic number, because the mean of its divisors is an integer number (2570040).

Almost surely, 2^25661145 is an apocalyptic number.

It is an amenable number.

25661145 is a deficient number, since it is larger than the sum of its proper divisors (15459495).

25661145 is a wasteful number, since it uses less digits than its factorization.

25661145 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2624.

The product of its digits is 7200, while the sum is 30.

The square root of 25661145 is about 5065.6830733870. The cubic root of 25661145 is about 294.9569792670.

Adding to 25661145 its reverse (54116652), we get a palindrome (79777797).

The spelling of 25661145 in words is "twenty-five million, six hundred sixty-one thousand, one hundred forty-five".