561281100 has 72 divisors (see below), whose sum is σ = 1631853888. Its totient is φ = 148948800.

The previous prime is 561281089. The next prime is 561281113. The reversal of 561281100 is 1182165.

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 23 ways as a sum of consecutive naturals, for example, 58867 + ... + 67733.

Almost surely, 2^561281100 is an apocalyptic number.

561281100 is a gapful number since it is divisible by the number (50) 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 561281100, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (815926944).

561281100 is an abundant number, since it is smaller than the sum of its proper divisors (1070572788).

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

561281100 is a wasteful number, since it uses less digits than its factorization.

561281100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9095 (or 9088 counting only the distinct ones).

The product of its (nonzero) digits is 480, while the sum is 24.

The square root of 561281100 is about 23691.3718471514. The cubic root of 561281100 is about 824.8851263381.

The spelling of 561281100 in words is "five hundred sixty-one million, two hundred eighty-one thousand, one hundred".