561001680 has 80 divisors (see below), whose sum is σ = 1932346560. Its totient is φ = 149599872.

The previous prime is 561001643. The next prime is 561001687. The reversal of 561001680 is 86100165.

It is a tau number, because it is divible by the number of its divisors (80).

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (561001687) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 127702 + ... + 132021.

It is an arithmetic number, because the mean of its divisors is an integer number (24154332).

Almost surely, 2^561001680 is an apocalyptic number.

It is an amenable number.

561001680 is an abundant number, since it is smaller than the sum of its proper divisors (1371344880).

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

561001680 is a wasteful number, since it uses less digits than its factorization.

561001680 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 259745 (or 259733 counting only the distinct ones).

The product of its (nonzero) digits is 1440, while the sum is 27.

The square root of 561001680 is about 23685.4740294553. The cubic root of 561001680 is about 824.7482206887.

The spelling of 561001680 in words is "five hundred sixty-one million, one thousand, six hundred eighty".