861365120 has 288 divisors, whose sum is σ = 2644556040. Its totient is φ = 267294720.

The previous prime is 861365083. The next prime is 861365147. The reversal of 861365120 is 21563168.

It is a happy number.

It is a super-2 number, since 2×861365120² = 1483899739905228800, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (32).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 3794447 + ... + 3794673.

Almost surely, 2^861365120 is an apocalyptic number.

861365120 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 861365120, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1322278020).

861365120 is an abundant number, since it is smaller than the sum of its proper divisors (1783190920).

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

861365120 is a wasteful number, since it uses less digits than its factorization.

861365120 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 282 (or 252 counting only the distinct ones).

The product of its (nonzero) digits is 8640, while the sum is 32.

The square root of 861365120 is about 29349.0224709444. The cubic root of 861365120 is about 951.4714482394.

The spelling of 861365120 in words is "eight hundred sixty-one million, three hundred sixty-five thousand, one hundred twenty".