21230339 has 4 divisors (see below), whose sum is σ = 22863456. Its totient is φ = 19597224.

The previous prime is 21230329. The next prime is 21230359. The reversal of 21230339 is 93303212.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21230339 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21230309) 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, 816539 + ... + 816564.

It is an arithmetic number, because the mean of its divisors is an integer number (5715864).

Almost surely, 2^21230339 is an apocalyptic number.

21230339 is a deficient number, since it is larger than the sum of its proper divisors (1633117).

21230339 is a wasteful number, since it uses less digits than its factorization.

21230339 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1633116.

The product of its (nonzero) digits is 972, while the sum is 23.

The square root of 21230339 is about 4607.6392002847. The cubic root of 21230339 is about 276.8974627761.

The spelling of 21230339 in words is "twenty-one million, two hundred thirty thousand, three hundred thirty-nine".