21023313 has 16 divisors (see below), whose sum is σ = 28771200. Its totient is φ = 13650560.

The previous prime is 21023309. The next prime is 21023323. The reversal of 21023313 is 31332012.

It is a cyclic number.

It is not a de Polignac number, because 21023313 - 2² = 21023309 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21023292 and 21023301.

It is not an unprimeable number, because it can be changed into a prime (21023323) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 18403 + ... + 19511.

It is an arithmetic number, because the mean of its divisors is an integer number (1798200).

Almost surely, 2^21023313 is an apocalyptic number.

It is an amenable number.

21023313 is a deficient number, since it is larger than the sum of its proper divisors (7747887).

21023313 is a wasteful number, since it uses less digits than its factorization.

21023313 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1272.

The product of its (nonzero) digits is 108, while the sum is 15.

The square root of 21023313 is about 4585.1186462293. The cubic root of 21023313 is about 275.9944732143.

Adding to 21023313 its reverse (31332012), we get a palindrome (52355325).

The spelling of 21023313 in words is "twenty-one million, twenty-three thousand, three hundred thirteen".