891820 has 48 divisors (see below), whose sum is σ = 2062368. Its totient is φ = 322560.

The previous prime is 891817. The next prime is 891823. The reversal of 891820 is 28198.

It is an interprime number because it is at equal distance from previous prime (891817) and next prime (891823).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (891823) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 14590 + ... + 14650.

It is an arithmetic number, because the mean of its divisors is an integer number (42966).

2⁸⁹¹⁸²⁰ 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 891820, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1031184).

891820 is an abundant number, since it is smaller than the sum of its proper divisors (1170548).

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

891820 is a wasteful number, since it uses less digits than its factorization.

891820 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 130 (or 128 counting only the distinct ones).

The product of its (nonzero) digits is 1152, while the sum is 28.

The square root of 891820 is about 944.3622186428. The cubic root of 891820 is about 96.2555402444.

It can be divided in two parts, 891 and 820, that added together give a triangular number (1711 = T₅₈).

The spelling of 891820 in words is "eight hundred ninety-one thousand, eight hundred twenty".