661361274725 has 12 divisors (see below), whose sum is σ = 824381640960. Its totient is φ = 526318916400.

The previous prime is 661361274689. The next prime is 661361274737. The reversal of 661361274725 is 527472163166.

It is not a de Polignac number, because 661361274725 - 2²⁴ = 661344497509 is a prime.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 69247715 + ... + 69257264.

It is an arithmetic number, because the mean of its divisors is an integer number (68698470080).

Almost surely, 2^661361274725 is an apocalyptic number.

It is an amenable number.

661361274725 is a deficient number, since it is larger than the sum of its proper divisors (163020366235).

661361274725 is a wasteful number, since it uses less digits than its factorization.

661361274725 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 138505180 (or 138505175 counting only the distinct ones).

The product of its digits is 2540160, while the sum is 50.

The spelling of 661361274725 in words is "six hundred sixty-one billion, three hundred sixty-one million, two hundred seventy-four thousand, seven hundred twenty-five".