890991 has 6 divisors (see below), whose sum is σ = 1287000. Its totient is φ = 593988.

The previous prime is 890969. The next prime is 890993. The reversal of 890991 is 199098.

It is not a de Polignac number, because 890991 - 2⁶ = 890927 is a prime.

890991 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (890993) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 49491 + ... + 49508.

It is an arithmetic number, because the mean of its divisors is an integer number (214500).

2⁸⁹⁰⁹⁹¹ is an apocalyptic number.

890991 is a deficient number, since it is larger than the sum of its proper divisors (396009).

890991 is a wasteful number, since it uses less digits than its factorization.

890991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 99005 (or 99002 counting only the distinct ones).

The product of its (nonzero) digits is 5832, while the sum is 36.

The square root of 890991 is about 943.9231960282. The cubic root of 890991 is about 96.2257059054.

It can be divided in two parts, 890 and 991, that added together give a palindrome (1881).

The spelling of 890991 in words is "eight hundred ninety thousand, nine hundred ninety-one".