25147105661 has 4 divisors (see below), whose sum is σ = 25429657500. Its totient is φ = 24864553824.

The previous prime is 25147105651. The next prime is 25147105679. The reversal of 25147105661 is 16650174152.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 8673383161 + 16473722500 = 93131^2 + 128350^2 .

It is a cyclic number.

It is not a de Polignac number, because 25147105661 - 2⁶ = 25147105597 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (25147105651) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 141275786 + ... + 141275963.

It is an arithmetic number, because the mean of its divisors is an integer number (6357414375).

Almost surely, 2^25147105661 is an apocalyptic number.

It is an amenable number.

25147105661 is a deficient number, since it is larger than the sum of its proper divisors (282551839).

25147105661 is an equidigital number, since it uses as much as digits as its factorization.

25147105661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 282551838.

The product of its (nonzero) digits is 50400, while the sum is 38.

The spelling of 25147105661 in words is "twenty-five billion, one hundred forty-seven million, one hundred five thousand, six hundred sixty-one".