561391837 has 4 divisors (see below), whose sum is σ = 561860476. Its totient is φ = 560923200.

The previous prime is 561391823. The next prime is 561391849. The reversal of 561391837 is 738193165.

561391837 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 75012921 + 486378916 = 8661^2 + 22054^2 .

It is a cyclic number.

It is not a de Polignac number, because 561391837 - 2²⁷ = 427174109 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 561391793 and 561391802.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (561391637) 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, 232518 + ... + 234919.

It is an arithmetic number, because the mean of its divisors is an integer number (140465119).

Almost surely, 2^561391837 is an apocalyptic number.

It is an amenable number.

561391837 is a deficient number, since it is larger than the sum of its proper divisors (468639).

561391837 is a wasteful number, since it uses less digits than its factorization.

561391837 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 468638.

The product of its digits is 136080, while the sum is 43.

The square root of 561391837 is about 23693.7088063477. The cubic root of 561391837 is about 824.9393708735.

The spelling of 561391837 in words is "five hundred sixty-one million, three hundred ninety-one thousand, eight hundred thirty-seven".