561609216 has 240 divisors, whose sum is σ = 1935483264. Its totient is φ = 153280512.

The previous prime is 561609203. The next prime is 561609241. The reversal of 561609216 is 612906165.

561609216 is a `hidden beast` number, since 561 + 6 + 0 + 92 + 1 + 6 = 666.

It is a super-2 number, since 2×561609216² = 630809822992269312, which contains 22 as substring.

It is a hoax number, since the sum of its digits (36) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (36).

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, 741510 + ... + 742266.

Almost surely, 2^561609216 is an apocalyptic number.

561609216 is a gapful number since it is divisible by the number (56) 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 561609216, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (967741632).

561609216 is an abundant number, since it is smaller than the sum of its proper divisors (1373874048).

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

561609216 is a wasteful number, since it uses less digits than its factorization.

561609216 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 811 (or 792 counting only the distinct ones).

The product of its (nonzero) digits is 19440, while the sum is 36.

The square root of 561609216 is about 23698.2956349186. The cubic root of 561609216 is about 825.0458332663.

The spelling of 561609216 in words is "five hundred sixty-one million, six hundred nine thousand, two hundred sixteen".