2123381 has 4 divisors (see below), whose sum is σ = 2286732. Its totient is φ = 1960032.

The previous prime is 2123377. The next prime is 2123411. The reversal of 2123381 is 1833212.

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 1416100 + 707281 = 1190^2 + 841^2 .

It is a cyclic number.

It is not a de Polignac number, because 2123381 - 2² = 2123377 is a prime.

It is a super-2 number, since 2×2123381² = 9017493742322, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2123081) 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, 81656 + ... + 81681.

It is an arithmetic number, because the mean of its divisors is an integer number (571683).

2^2123381 is an apocalyptic number.

It is an amenable number.

2123381 is a deficient number, since it is larger than the sum of its proper divisors (163351).

2123381 is a wasteful number, since it uses less digits than its factorization.

2123381 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 163350.

The product of its digits is 288, while the sum is 20.

The square root of 2123381 is about 1457.1825554816. The cubic root of 2123381 is about 128.5314210030.

Adding to 2123381 its reverse (1833212), we get a palindrome (3956593).

The spelling of 2123381 in words is "two million, one hundred twenty-three thousand, three hundred eighty-one".