21143331 has 24 divisors (see below), whose sum is σ = 34135920. Its totient is φ = 12499200.

The previous prime is 21143327. The next prime is 21143357. The reversal of 21143331 is 13334112.

It is not a de Polignac number, because 21143331 - 2² = 21143327 is a prime.

It is a super-2 number, since 2×21143331² = 894080891551122, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21123331) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1455 + ... + 6663.

It is an arithmetic number, because the mean of its divisors is an integer number (1422330).

Almost surely, 2^21143331 is an apocalyptic number.

21143331 is a deficient number, since it is larger than the sum of its proper divisors (12992589).

21143331 is a wasteful number, since it uses less digits than its factorization.

21143331 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5267 (or 5264 counting only the distinct ones).

The product of its digits is 216, while the sum is 18.

The square root of 21143331 is about 4598.1877952080. The cubic root of 21143331 is about 276.5186765188.

Adding to 21143331 its reverse (13334112), we get a palindrome (34477443).

It can be divided in two parts, 2114 and 3331, that added together give a palindrome (5445).

The spelling of 21143331 in words is "twenty-one million, one hundred forty-three thousand, three hundred thirty-one".