861534772 has 48 divisors (see below), whose sum is σ = 1832302080. Its totient is φ = 346010112.

The previous prime is 861534767. The next prime is 861534787. The reversal of 861534772 is 277435168.

Its product of digits (282240) is a multiple of the sum of its prime factors (7840).

It is a congruent number.

It is an unprimeable number.

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 15 ways as a sum of consecutive naturals, for example, 109978 + ... + 117550.

It is an arithmetic number, because the mean of its divisors is an integer number (38172960).

Almost surely, 2^861534772 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 861534772, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (916151040).

861534772 is an abundant number, since it is smaller than the sum of its proper divisors (970767308).

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

861534772 is a wasteful number, since it uses less digits than its factorization.

861534772 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7840 (or 7838 counting only the distinct ones).

The product of its digits is 282240, while the sum is 43.

The square root of 861534772 is about 29351.9125782290. The cubic root of 861534772 is about 951.5339105000.

The spelling of 861534772 in words is "eight hundred sixty-one million, five hundred thirty-four thousand, seven hundred seventy-two".