561923987 has 2 divisors, whose sum is σ = 561923988. Its totient is φ = 561923986.

The previous prime is 561923969. The next prime is 561924023. The reversal of 561923987 is 789329165.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 561923987 - 2¹⁴ = 561907603 is a prime.

It is not a weakly prime, because it can be changed into another prime (561923387) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 280961993 + 280961994.

It is an arithmetic number, because the mean of its divisors is an integer number (280961994).

Almost surely, 2^561923987 is an apocalyptic number.

561923987 is a deficient number, since it is larger than the sum of its proper divisors (1).

561923987 is an equidigital number, since it uses as much as digits as its factorization.

561923987 is an evil number, because the sum of its binary digits is even.

The product of its digits is 816480, while the sum is 50.

The square root of 561923987 is about 23704.9359206052. The cubic root of 561923987 is about 825.1999451711.

The spelling of 561923987 in words is "five hundred sixty-one million, nine hundred twenty-three thousand, nine hundred eighty-seven".