25661515 has 8 divisors (see below), whose sum is σ = 33593328. Its totient is φ = 18662880.

The previous prime is 25661513. The next prime is 25661527. The reversal of 25661515 is 51516652.

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

It is not a de Polignac number, because 25661515 - 2¹ = 25661513 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (25661513) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 233232 + ... + 233341.

It is an arithmetic number, because the mean of its divisors is an integer number (4199166).

Almost surely, 2^25661515 is an apocalyptic number.

25661515 is a deficient number, since it is larger than the sum of its proper divisors (7931813).

25661515 is a wasteful number, since it uses less digits than its factorization.

25661515 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 466589.

The product of its digits is 9000, while the sum is 31.

The square root of 25661515 is about 5065.7195935030. The cubic root of 25661515 is about 294.9583968909.

The spelling of 25661515 in words is "twenty-five million, six hundred sixty-one thousand, five hundred fifteen".