25666261517215 has 16 divisors (see below), whose sum is σ = 33603032964096. Its totient is φ = 18664392378400.

The previous prime is 25666261517207. The next prime is 25666261517227. The reversal of 25666261517215 is 51271516266652.

It is not a de Polignac number, because 25666261517215 - 2³ = 25666261517207 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (55).

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 24222007 + ... + 25259416.

It is an arithmetic number, because the mean of its divisors is an integer number (2100189560256).

Almost surely, 2^{25666261517215} is an apocalyptic number.

25666261517215 is a deficient number, since it is larger than the sum of its proper divisors (7936771446881).

25666261517215 is a wasteful number, since it uses less digits than its factorization.

25666261517215 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 49490870.

The product of its digits is 9072000, while the sum is 55.

The spelling of 25666261517215 in words is "twenty-five trillion, six hundred sixty-six billion, two hundred sixty-one million, five hundred seventeen thousand, two hundred fifteen".