1561372974765 has 40 divisors (see below), whose sum is σ = 2805369929208. Its totient is φ = 830808990720.

The previous prime is 1561372974737. The next prime is 1561372974773. The reversal of 1561372974765 is 5674792731651.

1561372974765 is a `hidden beast` number, since 1 + 5 + 6 + 1 + 3 + 72 + 97 + 476 + 5 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 70480692324 + 1490892282441 = 265482^2 + 1221021^2 .

It is not a de Polignac number, because 1561372974765 - 2⁹ = 1561372974253 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 4276416 + ... + 4627145.

Almost surely, 2^{1561372974765} is an apocalyptic number.

1561372974765 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1561372974765 is a deficient number, since it is larger than the sum of its proper divisors (1243996954443).

1561372974765 is an equidigital number, since it uses as much as digits as its factorization.

1561372974765 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8904011 (or 8904002 counting only the distinct ones).

The product of its digits is 66679200, while the sum is 63.

The spelling of 1561372974765 in words is "one trillion, five hundred sixty-one billion, three hundred seventy-two million, nine hundred seventy-four thousand, seven hundred sixty-five".