561432816 has 320 divisors, whose sum is σ = 1954160640. Its totient is φ = 150958080.

The previous prime is 561432793. The next prime is 561432821. The reversal of 561432816 is 618234165.

It is a happy number.

561432816 is a `hidden beast` number, since 5 + 614 + 3 + 28 + 16 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 4968376 + ... + 4968488.

It is an arithmetic number, because the mean of its divisors is an integer number (6106752).

Almost surely, 2^561432816 is an apocalyptic number.

561432816 is a gapful number since it is divisible by the number (56) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 561432816, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (977080320).

561432816 is an abundant number, since it is smaller than the sum of its proper divisors (1392727824).

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

561432816 is a wasteful number, since it uses less digits than its factorization.

561432816 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 221 (or 209 counting only the distinct ones).

The product of its digits is 34560, while the sum is 36.

The square root of 561432816 is about 23694.5735559853. The cubic root of 561432816 is about 824.9594426343.

The spelling of 561432816 in words is "five hundred sixty-one million, four hundred thirty-two thousand, eight hundred sixteen".