861867936 has 144 divisors (see below), whose sum is σ = 2604911400. Its totient is φ = 269789184.

The previous prime is 861867917. The next prime is 861867943. The reversal of 861867936 is 639768168.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 855211536 + 6656400 = 29244^2 + 2580^2 .

It is a tau number, because it is divible by the number of its divisors (144).

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, 307630 + ... + 310418.

Almost surely, 2^861867936 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 861867936, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1302455700).

861867936 is an abundant number, since it is smaller than the sum of its proper divisors (1743043464).

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

861867936 is a wasteful number, since it uses less digits than its factorization.

861867936 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2871 (or 2860 counting only the distinct ones).

The product of its digits is 2612736, while the sum is 54.

The square root of 861867936 is about 29357.5873668120. The cubic root of 861867936 is about 951.6565505444.

The spelling of 861867936 in words is "eight hundred sixty-one million, eight hundred sixty-seven thousand, nine hundred thirty-six".