561879240 has 128 divisors (see below), whose sum is σ = 1922175360. Its totient is φ = 130166784.

The previous prime is 561879239. The next prime is 561879271. The reversal of 561879240 is 42978165.

It is a junction number, because it is equal to n+sod(n) for n = 561879192 and 561879201.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 15927 + ... + 37113.

It is an arithmetic number, because the mean of its divisors is an integer number (15016995).

Almost surely, 2^561879240 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 561879240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (961087680).

561879240 is an abundant number, since it is smaller than the sum of its proper divisors (1360296120).

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

561879240 is a wasteful number, since it uses less digits than its factorization.

561879240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21231 (or 21227 counting only the distinct ones).

The product of its (nonzero) digits is 120960, while the sum is 42.

The square root of 561879240 is about 23703.9920688478. The cubic root of 561879240 is about 825.1780405464.

It can be divided in two parts, 561 and 879240, that added together give a triangular number (879801 = T₁₃₂₆).

The spelling of 561879240 in words is "five hundred sixty-one million, eight hundred seventy-nine thousand, two hundred forty".