25978515 has 16 divisors (see below), whose sum is σ = 41949600. Its totient is φ = 13727232.

The previous prime is 25978501. The next prime is 25978517. The reversal of 25978515 is 51587952.

It is not a de Polignac number, because 25978515 - 2¹⁵ = 25945747 is a prime.

It is not an unprimeable number, because it can be changed into a prime (25978517) 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, 6310 + ... + 9579.

It is an arithmetic number, because the mean of its divisors is an integer number (2621850).

Almost surely, 2^25978515 is an apocalyptic number.

25978515 is a deficient number, since it is larger than the sum of its proper divisors (15971085).

25978515 is a wasteful number, since it uses less digits than its factorization.

25978515 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16006.

The product of its digits is 126000, while the sum is 42.

The square root of 25978515 is about 5096.9123005993. The cubic root of 25978515 is about 296.1679827790.

The spelling of 25978515 in words is "twenty-five million, nine hundred seventy-eight thousand, five hundred fifteen".