561251100 has 72 divisors (see below), whose sum is σ = 1636784128. Its totient is φ = 148478400.

The previous prime is 561251081. The next prime is 561251101. The reversal of 561251100 is 1152165.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (561251101) 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 23 ways as a sum of consecutive naturals, for example, 30735 + ... + 45465.

Almost surely, 2^561251100 is an apocalyptic number.

561251100 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 561251100, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (818392064).

561251100 is an abundant number, since it is smaller than the sum of its proper divisors (1075533028).

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

561251100 is a wasteful number, since it uses less digits than its factorization.

561251100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14875 (or 14868 counting only the distinct ones).

The product of its (nonzero) digits is 300, while the sum is 21.

The square root of 561251100 is about 23690.7386967988. The cubic root of 561251100 is about 824.8704296055.

The spelling of 561251100 in words is "five hundred sixty-one million, two hundred fifty-one thousand, one hundred".