2561651431366 has 4 divisors (see below), whose sum is σ = 3842477147052. Its totient is φ = 1280825715682.

The previous prime is 2561651431363. The next prime is 2561651431369. The reversal of 2561651431366 is 6631341561652.

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

It is an interprime number because it is at equal distance from previous prime (2561651431363) and next prime (2561651431369).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2561651431363) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 640412857840 + ... + 640412857843.

It is an arithmetic number, because the mean of its divisors is an integer number (960619286763).

Almost surely, 2^{2561651431366} is an apocalyptic number.

2561651431366 is a deficient number, since it is larger than the sum of its proper divisors (1280825715686).

2561651431366 is a wasteful number, since it uses less digits than its factorization.

2561651431366 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1280825715685.

The product of its digits is 2332800, while the sum is 49.

The spelling of 2561651431366 in words is "two trillion, five hundred sixty-one billion, six hundred fifty-one million, four hundred thirty-one thousand, three hundred sixty-six".