21142323 has 16 divisors (see below), whose sum is σ = 31393440. Its totient is φ = 14062752.

The previous prime is 21142291. The next prime is 21142343. The reversal of 21142323 is 32324112.

It is not a de Polignac number, because 21142323 - 2⁵ = 21142291 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21142296 and 21142305.

It is not an unprimeable number, because it can be changed into a prime (21142343) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 20365 + ... + 21377.

It is an arithmetic number, because the mean of its divisors is an integer number (1962090).

Almost surely, 2^21142323 is an apocalyptic number.

21142323 is a deficient number, since it is larger than the sum of its proper divisors (10251117).

21142323 is a wasteful number, since it uses less digits than its factorization.

21142323 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1795 (or 1789 counting only the distinct ones).

The product of its digits is 288, while the sum is 18.

The square root of 21142323 is about 4598.0781855032. The cubic root of 21142323 is about 276.5142821425.

Adding to 21142323 its reverse (32324112), we get a palindrome (53466435).

The spelling of 21142323 in words is "twenty-one million, one hundred forty-two thousand, three hundred twenty-three".