890921 has 4 divisors (see below), whose sum is σ = 899844. Its totient is φ = 882000.

The previous prime is 890893. The next prime is 890927. The reversal of 890921 is 129098.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 739600 + 151321 = 860^2 + 389^2 .

It is a cyclic number.

It is not a de Polignac number, because 890921 - 2¹⁴ = 874537 is a prime.

It is an alternating number because its digits alternate between even and odd.

It is a Duffinian number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 890921.

It is not an unprimeable number, because it can be changed into a prime (890927) 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, 4310 + ... + 4511.

It is an arithmetic number, because the mean of its divisors is an integer number (224961).

2⁸⁹⁰⁹²¹ is an apocalyptic number.

It is an amenable number.

890921 is a deficient number, since it is larger than the sum of its proper divisors (8923).

890921 is a wasteful number, since it uses less digits than its factorization.

890921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8922.

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

The square root of 890921 is about 943.8861160119. The cubic root of 890921 is about 96.2231858740.

The spelling of 890921 in words is "eight hundred ninety thousand, nine hundred twenty-one".