21423001 has 4 divisors (see below), whose sum is σ = 21433600. Its totient is φ = 21412404.

The previous prime is 21422993. The next prime is 21423007. The reversal of 21423001 is 10032412.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 21423001 - 2³ = 21422993 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21423007) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1221 + ... + 6658.

It is an arithmetic number, because the mean of its divisors is an integer number (5358400).

Almost surely, 2^21423001 is an apocalyptic number.

It is an amenable number.

21423001 is a deficient number, since it is larger than the sum of its proper divisors (10599).

21423001 is an equidigital number, since it uses as much as digits as its factorization.

21423001 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10598.

The product of its (nonzero) digits is 48, while the sum is 13.

The square root of 21423001 is about 4628.4987847033. The cubic root of 21423001 is about 277.7325421390.

Adding to 21423001 its reverse (10032412), we get a palindrome (31455413).

The spelling of 21423001 in words is "twenty-one million, four hundred twenty-three thousand, one".