561786091 has 4 divisors (see below), whose sum is σ = 591353800. Its totient is φ = 532218384.

The previous prime is 561786083. The next prime is 561786103. The reversal of 561786091 is 190687165.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 190687165 = 5 ⋅38137433.

It is a cyclic number.

It is not a de Polignac number, because 561786091 - 2³ = 561786083 is a prime.

It is a super-2 number, since 2×561786091² = 631207224082120562, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (561786011) 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, 14783826 + ... + 14783863.

It is an arithmetic number, because the mean of its divisors is an integer number (147838450).

Almost surely, 2^561786091 is an apocalyptic number.

561786091 is a deficient number, since it is larger than the sum of its proper divisors (29567709).

561786091 is a wasteful number, since it uses less digits than its factorization.

561786091 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 29567708.

The product of its (nonzero) digits is 90720, while the sum is 43.

The square root of 561786091 is about 23702.0271495921. The cubic root of 561786091 is about 825.1324383649.

The spelling of 561786091 in words is "five hundred sixty-one million, seven hundred eighty-six thousand, ninety-one".