561081613 has 4 divisors (see below), whose sum is σ = 561222208. Its totient is φ = 560941020.

The previous prime is 561081581. The next prime is 561081623. The reversal of 561081613 is 316180165.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 561081613 - 2⁵ = 561081581 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (561081623) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 64131 + ... + 72352.

It is an arithmetic number, because the mean of its divisors is an integer number (140305552).

Almost surely, 2^561081613 is an apocalyptic number.

It is an amenable number.

561081613 is a deficient number, since it is larger than the sum of its proper divisors (140595).

561081613 is a wasteful number, since it uses less digits than its factorization.

561081613 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 140594.

The product of its (nonzero) digits is 4320, while the sum is 31.

The square root of 561081613 is about 23687.1613537798. The cubic root of 561081613 is about 824.7873895962.

It can be divided in two parts, 5610 and 81613, that multiplied together give a triangular number (457848930 = T₃₀₂₆₀).

The spelling of 561081613 in words is "five hundred sixty-one million, eighty-one thousand, six hundred thirteen".