21023733 has 12 divisors (see below), whose sum is σ = 28815360. Its totient is φ = 13634352.

The previous prime is 21023731. The next prime is 21023741. The reversal of 21023733 is 33732012.

It is not a de Polignac number, because 21023733 - 2¹ = 21023731 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21023731) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1548 + ... + 6666.

It is an arithmetic number, because the mean of its divisors is an integer number (2401280).

Almost surely, 2^21023733 is an apocalyptic number.

It is an amenable number.

21023733 is a deficient number, since it is larger than the sum of its proper divisors (7791627).

21023733 is an equidigital number, since it uses as much as digits as its factorization.

21023733 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5196 (or 5159 counting only the distinct ones).

The product of its (nonzero) digits is 756, while the sum is 21.

The square root of 21023733 is about 4585.1644463421. The cubic root of 21023733 is about 275.9963111248.

Adding to 21023733 its reverse (33732012), we get a palindrome (54755745).

The spelling of 21023733 in words is "twenty-one million, twenty-three thousand, seven hundred thirty-three".