21023331 has 16 divisors (see below), whose sum is σ = 32218368. Its totient is φ = 11944800.

The previous prime is 21023323. The next prime is 21023341. The reversal of 21023331 is 13332012.

It is not a de Polignac number, because 21023331 - 2³ = 21023323 is a prime.

It is a super-2 number, since 2×21023331² = 883960892671122, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 21023331.

It is not an unprimeable number, because it can be changed into a prime (21023341) 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, 1036 + ... + 6566.

It is an arithmetic number, because the mean of its divisors is an integer number (2013648).

Almost surely, 2^21023331 is an apocalyptic number.

21023331 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

21023331 is a deficient number, since it is larger than the sum of its proper divisors (11195037).

21023331 is a wasteful number, since it uses less digits than its factorization.

21023331 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5722.

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

The square root of 21023331 is about 4585.1206091007. The cubic root of 21023331 is about 275.9945519824.

Adding to 21023331 its reverse (13332012), we get a palindrome (34355343).

The spelling of 21023331 in words is "twenty-one million, twenty-three thousand, three hundred thirty-one".