2561491730792 has 8 divisors (see below), whose sum is σ = 4802796995250. Its totient is φ = 1280745865392.

The previous prime is 2561491730789. The next prime is 2561491730797. The reversal of 2561491730792 is 2970371941652.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 2221035818596 + 340455912196 = 1490314^2 + 583486^2 .

It is a tau number, because it is divible by the number of its divisors (8).

It is a super-2 number, since 2×2561491730792² (a number of 26 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (2561491730797) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 160093233167 + ... + 160093233182.

Almost surely, 2^{2561491730792} is an apocalyptic number.

It is an amenable number.

2561491730792 is a deficient number, since it is larger than the sum of its proper divisors (2241305264458).

2561491730792 is a wasteful number, since it uses less digits than its factorization.

2561491730792 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 320186466355 (or 320186466351 counting only the distinct ones).

The product of its (nonzero) digits is 5715360, while the sum is 56.

The spelling of 2561491730792 in words is "two trillion, five hundred sixty-one billion, four hundred ninety-one million, seven hundred thirty thousand, seven hundred ninety-two".