861622272 has 390 divisors, whose sum is σ = 3050639658. Its totient is φ = 241532928.

The previous prime is 861622247. The next prime is 861622273. The reversal of 861622272 is 272226168.

861622272 is a `hidden beast` number, since 8 + 6 + 1 + 622 + 27 + 2 = 666.

It can be written as a sum of positive squares in only one way, i.e., 796594176 + 65028096 = 28224^2 + 8064^2 .

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

It is a nude number because it is divisible by every one of its digits and also a Zuckerman number because it is divisible by the product of its digits.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (861622273) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 29 ways as a sum of consecutive naturals, for example, 16256998 + ... + 16257050.

Almost surely, 2^861622272 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 861622272, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1525319829).

861622272 is an abundant number, since it is smaller than the sum of its proper divisors (2189017386).

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

861622272 is an equidigital number, since it uses as much as digits as its factorization.

861622272 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 103 (or 65 counting only the distinct ones).

The product of its digits is 32256, while the sum is 36.

The square root of 861622272 is about 29353.4030735790. The cubic root of 861622272 is about 951.5661229351.

The spelling of 861622272 in words is "eight hundred sixty-one million, six hundred twenty-two thousand, two hundred seventy-two".