2561401365 has 32 divisors (see below), whose sum is σ = 4244244480. Its totient is φ = 1317517824.

The previous prime is 2561401361. The next prime is 2561401379. The reversal of 2561401365 is 5631041652.

It is not a de Polignac number, because 2561401365 - 2² = 2561401361 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2561401361) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 470137 + ... + 475553.

It is an arithmetic number, because the mean of its divisors is an integer number (132632640).

Almost surely, 2^2561401365 is an apocalyptic number.

It is an amenable number.

2561401365 is a deficient number, since it is larger than the sum of its proper divisors (1682843115).

2561401365 is a wasteful number, since it uses less digits than its factorization.

2561401365 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6541.

The product of its (nonzero) digits is 21600, while the sum is 33.

The square root of 2561401365 is about 50610.2891218772. The cubic root of 2561401365 is about 1368.2303264376.

The spelling of 2561401365 in words is "two billion, five hundred sixty-one million, four hundred one thousand, three hundred sixty-five".