891640 has 16 divisors (see below), whose sum is σ = 2006280. Its totient is φ = 356640.

The previous prime is 891629. The next prime is 891643. The reversal of 891640 is 46198.

It is a junction number, because it is equal to n+sod(n) for n = 891599 and 891608.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (891643) by changing a digit.

891640 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, 11106 + ... + 11185.

2⁸⁹¹⁶⁴⁰ is an apocalyptic number.

It is an amenable number.

891640 is an abundant number, since it is smaller than the sum of its proper divisors (1114640).

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

891640 is a wasteful number, since it uses less digits than its factorization.

891640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22302 (or 22298 counting only the distinct ones).

The product of its (nonzero) digits is 1728, while the sum is 28.

The square root of 891640 is about 944.2669114186. The cubic root of 891640 is about 96.2490639140.

The spelling of 891640 in words is "eight hundred ninety-one thousand, six hundred forty".