861590772 has 72 divisors (see below), whose sum is σ = 2498228096. Its totient is φ = 245260224.

The previous prime is 861590767. The next prime is 861590773. The reversal of 861590772 is 277095168.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (861590773) 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, 63633 + ... + 75975.

Almost surely, 2^861590772 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 861590772, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1249114048).

861590772 is an abundant number, since it is smaller than the sum of its proper divisors (1636637324).

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

861590772 is a wasteful number, since it uses less digits than its factorization.

861590772 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12637 (or 12632 counting only the distinct ones).

The product of its (nonzero) digits is 211680, while the sum is 45.

The square root of 861590772 is about 29352.8665039720. The cubic root of 861590772 is about 951.5545267097.

The spelling of 861590772 in words is "eight hundred sixty-one million, five hundred ninety thousand, seven hundred seventy-two".