561616636 has 72 divisors (see below), whose sum is σ = 1202164656. Its totient is φ = 228614400.

The previous prime is 561616631. The next prime is 561616721. The reversal of 561616636 is 636616165.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (561616631) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 310936 + ... + 312736.

Almost surely, 2^561616636 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 561616636, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (601082328).

561616636 is an abundant number, since it is smaller than the sum of its proper divisors (640548020).

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

561616636 is a wasteful number, since it uses less digits than its factorization.

561616636 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1899 (or 1890 counting only the distinct ones).

The product of its digits is 116640, while the sum is 40.

The square root of 561616636 is about 23698.4521857441. The cubic root of 561616636 is about 825.0494667615.

The spelling of 561616636 in words is "five hundred sixty-one million, six hundred sixteen thousand, six hundred thirty-six".