561265003261 has 16 divisors (see below), whose sum is σ = 572863027968. Its totient is φ = 549772876800.

The previous prime is 561265003253. The next prime is 561265003331. The reversal of 561265003261 is 162300562165.

It is a cyclic number.

It is not a de Polignac number, because 561265003261 - 2³ = 561265003253 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 561265003261.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (561265003861) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 26323741 + ... + 26345053.

It is an arithmetic number, because the mean of its divisors is an integer number (35803939248).

Almost surely, 2^561265003261 is an apocalyptic number.

It is an amenable number.

561265003261 is a deficient number, since it is larger than the sum of its proper divisors (11598024707).

561265003261 is a wasteful number, since it uses less digits than its factorization.

561265003261 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23772.

The product of its (nonzero) digits is 64800, while the sum is 37.

The spelling of 561265003261 in words is "five hundred sixty-one billion, two hundred sixty-five million, three thousand, two hundred sixty-one".