21333013 has 8 divisors (see below), whose sum is σ = 23020088. Its totient is φ = 19652544.

The previous prime is 21333007. The next prime is 21333019. The reversal of 21333013 is 31033312.

It is an interprime number because it is at equal distance from previous prime (21333007) and next prime (21333019).

It can be written as a sum of positive squares in 4 ways, for example, as 4743684 + 16589329 = 2178^2 + 4073^2 .

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 21333013 - 2²¹ = 19235861 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21333019) 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, 6631 + ... + 9307.

It is an arithmetic number, because the mean of its divisors is an integer number (2877511).

Almost surely, 2^21333013 is an apocalyptic number.

It is an amenable number.

21333013 is a deficient number, since it is larger than the sum of its proper divisors (1687075).

21333013 is a wasteful number, since it uses less digits than its factorization.

21333013 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3303.

The product of its (nonzero) digits is 162, while the sum is 16.

The square root of 21333013 is about 4618.7674762863. The cubic root of 21333013 is about 277.3431215663.

Adding to 21333013 its reverse (31033312), we get a palindrome (52366325).

The spelling of 21333013 in words is "twenty-one million, three hundred thirty-three thousand, thirteen".