921816 has 96 divisors (see below), whose sum is σ = 2995200. Its totient is φ = 250560.

The previous prime is 921787. The next prime is 921821. The reversal of 921816 is 618129.

It is a nude number because it is divisible by every one of its digits.

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

It is a self number, because there is not a number n which added to its sum of digits gives 921816.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 15595 + ... + 15653.

It is an arithmetic number, because the mean of its divisors is an integer number (31200).

2⁹²¹⁸¹⁶ 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 921816, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1497600).

921816 is an abundant number, since it is smaller than the sum of its proper divisors (2073384).

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

921816 is a wasteful number, since it uses less digits than its factorization.

921816 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 109 (or 102 counting only the distinct ones).

The product of its digits is 864, while the sum is 27.

The square root of 921816 is about 960.1124934090. The cubic root of 921816 is about 97.3228340878.

The spelling of 921816 in words is "nine hundred twenty-one thousand, eight hundred sixteen".