21233929 has 4 divisors (see below), whose sum is σ = 21243600. Its totient is φ = 21224260.

The previous prime is 21233911. The next prime is 21233939. The reversal of 21233929 is 92933212.

It is a happy number.

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 21233929 - 2¹⁹ = 20709641 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21233929.

It is not an unprimeable number, because it can be changed into a prime (21233909) 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, 222 + ... + 6520.

It is an arithmetic number, because the mean of its divisors is an integer number (5310900).

Almost surely, 2^21233929 is an apocalyptic number.

It is an amenable number.

21233929 is a deficient number, since it is larger than the sum of its proper divisors (9671).

21233929 is an equidigital number, since it uses as much as digits as its factorization.

21233929 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9670.

The product of its digits is 5832, while the sum is 31.

The square root of 21233929 is about 4608.0287542506. The cubic root of 21233929 is about 276.9130694646.

The spelling of 21233929 in words is "twenty-one million, two hundred thirty-three thousand, nine hundred twenty-nine".