561481920 has 336 divisors, whose sum is σ = 2104826880. Its totient is φ = 136857600.

The previous prime is 561481903. The next prime is 561481961. The reversal of 561481920 is 29184165.

561481920 is a `hidden beast` number, since 5 + 614 + 8 + 19 + 20 = 666.

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 47 ways as a sum of consecutive naturals, for example, 1696155 + ... + 1696485.

Almost surely, 2^561481920 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 561481920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1052413440).

561481920 is an abundant number, since it is smaller than the sum of its proper divisors (1543344960).

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

561481920 is a wasteful number, since it uses less digits than its factorization.

561481920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 404 (or 391 counting only the distinct ones).

The product of its (nonzero) digits is 17280, while the sum is 36.

The square root of 561481920 is about 23695.6097199460. The cubic root of 561481920 is about 824.9834927827.

The spelling of 561481920 in words is "five hundred sixty-one million, four hundred eighty-one thousand, nine hundred twenty".