21242023 has 4 divisors (see below), whose sum is σ = 23173128. Its totient is φ = 19310920.

The previous prime is 21241991. The next prime is 21242047. The reversal of 21242023 is 32024212.

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

It is a cyclic number.

It is not a de Polignac number, because 21242023 - 2⁵ = 21241991 is a prime.

It is a super-2 number, since 2×21242023² = 902447082265058, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21241988 and 21242006.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21242063) 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, 965536 + ... + 965557.

It is an arithmetic number, because the mean of its divisors is an integer number (5793282).

Almost surely, 2^21242023 is an apocalyptic number.

21242023 is a deficient number, since it is larger than the sum of its proper divisors (1931105).

21242023 is a wasteful number, since it uses less digits than its factorization.

21242023 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1931104.

The product of its (nonzero) digits is 192, while the sum is 16.

The square root of 21242023 is about 4608.9069203012. The cubic root of 21242023 is about 276.9482497910.

Adding to 21242023 its reverse (32024212), we get a palindrome (53266235).

The spelling of 21242023 in words is "twenty-one million, two hundred forty-two thousand, twenty-three".