21223937 has 8 divisors (see below), whose sum is σ = 24847872. Its totient is φ = 17748000.

The previous prime is 21223927. The next prime is 21223957. The reversal of 21223937 is 73932212.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21223937 - 2¹⁰ = 21222913 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21223927) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 36689 + ... + 37262.

It is an arithmetic number, because the mean of its divisors is an integer number (3105984).

Almost surely, 2^21223937 is an apocalyptic number.

It is an amenable number.

21223937 is a deficient number, since it is larger than the sum of its proper divisors (3623935).

21223937 is an equidigital number, since it uses as much as digits as its factorization.

21223937 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 73999.

The product of its digits is 4536, while the sum is 29.

The square root of 21223937 is about 4606.9444320504. The cubic root of 21223937 is about 276.8696272059.

The spelling of 21223937 in words is "twenty-one million, two hundred twenty-three thousand, nine hundred thirty-seven".