21334331 has 4 divisors (see below), whose sum is σ = 21545664. Its totient is φ = 21123000.

The previous prime is 21334319. The next prime is 21334333. The reversal of 21334331 is 13343312.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21334331 - 2¹⁸ = 21072187 is a prime.

It is a super-2 number, since 2×21334331² = 910307358435122, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21334333) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 105515 + ... + 105716.

It is an arithmetic number, because the mean of its divisors is an integer number (5386416).

Almost surely, 2^21334331 is an apocalyptic number.

21334331 is a deficient number, since it is larger than the sum of its proper divisors (211333).

21334331 is a wasteful number, since it uses less digits than its factorization.

21334331 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 211332.

The product of its digits is 648, while the sum is 20.

The square root of 21334331 is about 4618.9101528391. The cubic root of 21334331 is about 277.3488330693.

Adding to 21334331 its reverse (13343312), we get a palindrome (34677643).

It can be divided in two parts, 2 and 1334331, that multiplied together give a palindrome (2668662).

The spelling of 21334331 in words is "twenty-one million, three hundred thirty-four thousand, three hundred thirty-one".