561816255 has 256 divisors, whose sum is σ = 1337720832. Its totient is φ = 193536000.

The previous prime is 561816253. The next prime is 561816257. The reversal of 561816255 is 552618165.

It is an interprime number because it is at equal distance from previous prime (561816253) and next prime (561816257).

It is not a de Polignac number, because 561816255 - 2¹ = 561816253 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (39).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (561816253) 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 255 ways as a sum of consecutive naturals, for example, 7912870 + ... + 7912940.

It is an arithmetic number, because the mean of its divisors is an integer number (5225472).

Almost surely, 2^561816255 is an apocalyptic number.

561816255 is a gapful number since it is divisible by the number (55) formed by its first and last digit.

561816255 is an abundant number, since it is smaller than the sum of its proper divisors (775904577).

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

561816255 is a wasteful number, since it uses less digits than its factorization.

561816255 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 158.

The product of its digits is 72000, while the sum is 39.

The square root of 561816255 is about 23702.6634579323. The cubic root of 561816255 is about 825.1472060555.

The spelling of 561816255 in words is "five hundred sixty-one million, eight hundred sixteen thousand, two hundred fifty-five".