891920 has 20 divisors (see below), whose sum is σ = 2073900. Its totient is φ = 356736.

The previous prime is 891907. The next prime is 891923. The reversal of 891920 is 29198.

It can be written as a sum of positive squares in 2 ways, for example, as 295936 + 595984 = 544^2 + 772^2 .

It is a tau number, because it is divible by the number of its divisors (20).

It is a Smith number, since the sum of its digits (29) coincides with the sum of the digits of its prime factors.

It is not an unprimeable number, because it can be changed into a prime (891923) by changing a digit.

891920 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5495 + ... + 5654.

It is an arithmetic number, because the mean of its divisors is an integer number (103695).

2⁸⁹¹⁹²⁰ is an apocalyptic number.

891920 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

891920 is an abundant number, since it is smaller than the sum of its proper divisors (1181980).

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

891920 is a wasteful number, since it uses less digits than its factorization.

891920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11162 (or 11156 counting only the distinct ones).

The product of its (nonzero) digits is 1296, while the sum is 29.

The square root of 891920 is about 944.4151629448. The cubic root of 891920 is about 96.2591378292.

The spelling of 891920 in words is "eight hundred ninety-one thousand, nine hundred twenty".