561123816 has 32 divisors (see below), whose sum is σ = 1530338400. Its totient is φ = 170037440.

The previous prime is 561123791. The next prime is 561123851. The reversal of 561123816 is 618321165.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1062471 + ... + 1062998.

It is an arithmetic number, because the mean of its divisors is an integer number (47823075).

Almost surely, 2^561123816 is an apocalyptic number.

It is an amenable number.

561123816 is an abundant number, since it is smaller than the sum of its proper divisors (969214584).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

561123816 is a wasteful number, since it uses less digits than its factorization.

561123816 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2125489 (or 2125485 counting only the distinct ones).

The product of its digits is 8640, while the sum is 33.

The square root of 561123816 is about 23688.0521782607. The cubic root of 561123816 is about 824.8080684830.

The spelling of 561123816 in words is "five hundred sixty-one million, one hundred twenty-three thousand, eight hundred sixteen".