2021923 has 4 divisors (see below), whose sum is σ = 2128360. Its totient is φ = 1915488.

The previous prime is 2021891. The next prime is 2021927. The reversal of 2021923 is 3291202.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 3291202 = 2 ⋅1645601.

It is a cyclic number.

It is not a de Polignac number, because 2021923 - 2⁵ = 2021891 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (19), and also a Moran number because the ratio is a prime number: 106417 = 2021923 / (2 + 0 + 2 + 1 + 9 + 2 + 3).

It is a Duffinian number.

2021923 is a lucky number.

It is a self number, because there is not a number n which added to its sum of digits gives 2021923.

It is not an unprimeable number, because it can be changed into a prime (2021927) 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, 53190 + ... + 53227.

It is an arithmetic number, because the mean of its divisors is an integer number (532090).

2^2021923 is an apocalyptic number.

2021923 is a deficient number, since it is larger than the sum of its proper divisors (106437).

2021923 is a wasteful number, since it uses less digits than its factorization.

2021923 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 106436.

The product of its (nonzero) digits is 216, while the sum is 19.

The square root of 2021923 is about 1421.9433884652. The cubic root of 2021923 is about 126.4507872541.

The spelling of 2021923 in words is "two million, twenty-one thousand, nine hundred twenty-three".