561777120 has 144 divisors (see below), whose sum is σ = 1988204400. Its totient is φ = 149796864.

The previous prime is 561777113. The next prime is 561777143. The reversal of 561777120 is 21777165.

561777120 is a `hidden beast` number, since 561 + 7 + 7 + 71 + 20 = 666.

It is a tau number, because it is divible by the number of its divisors (144).

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 23 ways as a sum of consecutive naturals, for example, 31656 + ... + 46104.

It is an arithmetic number, because the mean of its divisors is an integer number (13806975).

Almost surely, 2^561777120 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 561777120, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (994102200).

561777120 is an abundant number, since it is smaller than the sum of its proper divisors (1426427280).

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

561777120 is a wasteful number, since it uses less digits than its factorization.

561777120 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14479 (or 14459 counting only the distinct ones).

The product of its (nonzero) digits is 20580, while the sum is 36.

The square root of 561777120 is about 23701.8379034201. The cubic root of 561777120 is about 825.1280462409.

The spelling of 561777120 in words is "five hundred sixty-one million, seven hundred seventy-seven thousand, one hundred twenty".