561551720 has 32 divisors (see below), whose sum is σ = 1264273920. Its totient is φ = 224481600.

The previous prime is 561551719. The next prime is 561551741. The reversal of 561551720 is 27155165.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 82445 + ... + 88995.

It is an arithmetic number, because the mean of its divisors is an integer number (39508560).

Almost surely, 2^561551720 is an apocalyptic number.

It is an amenable number.

561551720 is an abundant number, since it is smaller than the sum of its proper divisors (702722200).

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

561551720 is a wasteful number, since it uses less digits than its factorization.

561551720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8705 (or 8701 counting only the distinct ones).

The product of its (nonzero) digits is 10500, while the sum is 32.

The square root of 561551720 is about 23697.0825208505. The cubic root of 561551720 is about 825.0176770011.

It can be divided in two parts, 56155 and 1720, that added together give a palindrome (57875).

The spelling of 561551720 in words is "five hundred sixty-one million, five hundred fifty-one thousand, seven hundred twenty".