25661537 has 8 divisors (see below), whose sum is σ = 29211840. Its totient is φ = 22314160.

The previous prime is 25661527. The next prime is 25661561. The reversal of 25661537 is 73516652.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 25661537 - 2¹⁰ = 25660513 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 25661497 and 25661506.

It is not an unprimeable number, because it can be changed into a prime (25661527) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 50462 + ... + 50967.

It is an arithmetic number, because the mean of its divisors is an integer number (3651480).

Almost surely, 2^25661537 is an apocalyptic number.

It is an amenable number.

25661537 is a deficient number, since it is larger than the sum of its proper divisors (3550303).

25661537 is a wasteful number, since it uses less digits than its factorization.

25661537 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 101463.

The product of its digits is 37800, while the sum is 35.

The square root of 25661537 is about 5065.7217649610. The cubic root of 25661537 is about 294.9584811816.

It can be divided in two parts, 256615 and 37, that added together give a palindrome (256652).

The spelling of 25661537 in words is "twenty-five million, six hundred sixty-one thousand, five hundred thirty-seven".