25515513 has 16 divisors (see below), whose sum is σ = 38139840. Its totient is φ = 16857792.

The previous prime is 25515509. The next prime is 25515551. The reversal of 25515513 is 31551552.

It is not a de Polignac number, because 25515513 - 2² = 25515509 is a prime.

It is a super-3 number, since 3×25515513³ (a number of 23 digits) contains 333 as substring.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is not an unprimeable number, because it can be changed into a prime (25515593) 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, 1131 + ... + 7232.

It is an arithmetic number, because the mean of its divisors is an integer number (2383740).

Almost surely, 2^25515513 is an apocalyptic number.

It is an amenable number.

25515513 is a deficient number, since it is larger than the sum of its proper divisors (12624327).

25515513 is a wasteful number, since it uses less digits than its factorization.

25515513 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8485 (or 8479 counting only the distinct ones).

The product of its digits is 3750, while the sum is 27.

The square root of 25515513 is about 5051.2882515255. The cubic root of 25515513 is about 294.3979409279.

The spelling of 25515513 in words is "twenty-five million, five hundred fifteen thousand, five hundred thirteen".