561055491 has 40 divisors (see below), whose sum is σ = 889077024. Its totient is φ = 351838080.

The previous prime is 561055487. The next prime is 561055499. The reversal of 561055491 is 194550165.

561055491 is a `hidden beast` number, since 5 + 6 + 10 + 554 + 91 = 666.

It is not a de Polignac number, because 561055491 - 2² = 561055487 is a prime.

It is not an unprimeable number, because it can be changed into a prime (561055499) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 111175 + ... + 116111.

Almost surely, 2^561055491 is an apocalyptic number.

561055491 is a deficient number, since it is larger than the sum of its proper divisors (328021533).

561055491 is a wasteful number, since it uses less digits than its factorization.

561055491 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5033 (or 5024 counting only the distinct ones).

The product of its (nonzero) digits is 27000, while the sum is 36.

The square root of 561055491 is about 23686.6099516161. The cubic root of 561055491 is about 824.7745896576.

The spelling of 561055491 in words is "five hundred sixty-one million, fifty-five thousand, four hundred ninety-one".