861920 has 24 divisors (see below), whose sum is σ = 2036664. Its totient is φ = 344704.

The previous prime is 861907. The next prime is 861929. The reversal of 861920 is 29168.

It is a self number, because there is not a number n which added to its sum of digits gives 861920.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (861929) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2534 + ... + 2853.

It is an arithmetic number, because the mean of its divisors is an integer number (84861).

2⁸⁶¹⁹²⁰ is an apocalyptic number.

861920 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

861920 is an abundant number, since it is smaller than the sum of its proper divisors (1174744).

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

861920 is a wasteful number, since it uses less digits than its factorization.

861920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5402 (or 5394 counting only the distinct ones).

The product of its (nonzero) digits is 864, while the sum is 26.

The square root of 861920 is about 928.3964670333. The cubic root of 861920 is about 95.1675712819.

The spelling of 861920 in words is "eight hundred sixty-one thousand, nine hundred twenty".