561626091 has 24 divisors (see below), whose sum is σ = 876913856. Its totient is φ = 344321280.

The previous prime is 561626083. The next prime is 561626113. The reversal of 561626091 is 190626165.

561626091 is a `hidden beast` number, since 561 + 6 + 2 + 6 + 0 + 91 = 666.

It is not a de Polignac number, because 561626091 - 2³ = 561626083 is a prime.

It is a hoax number, since the sum of its digits (36) coincides with the sum of the digits of its distinct prime factors.

It is not an unprimeable number, because it can be changed into a prime (561626041) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 22851 + ... + 40563.

Almost surely, 2^561626091 is an apocalyptic number.

561626091 is a deficient number, since it is larger than the sum of its proper divisors (315287765).

561626091 is a wasteful number, since it uses less digits than its factorization.

561626091 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18003 (or 18000 counting only the distinct ones).

The product of its (nonzero) digits is 19440, while the sum is 36.

The square root of 561626091 is about 23698.6516705065. The cubic root of 561626091 is about 825.0540967282.

The spelling of 561626091 in words is "five hundred sixty-one million, six hundred twenty-six thousand, ninety-one".