21336331 has 2 divisors, whose sum is σ = 21336332. Its totient is φ = 21336330.

The previous prime is 21336323. The next prime is 21336349. The reversal of 21336331 is 13363312.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21336331 - 2³ = 21336323 is a prime.

It is a super-2 number, since 2×21336331² = 910478041083122, which contains 22 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (21336391) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10668165 + 10668166.

It is an arithmetic number, because the mean of its divisors is an integer number (10668166).

Almost surely, 2^21336331 is an apocalyptic number.

21336331 is a deficient number, since it is larger than the sum of its proper divisors (1).

21336331 is an equidigital number, since it uses as much as digits as its factorization.

21336331 is an evil number, because the sum of its binary digits is even.

The product of its digits is 972, while the sum is 22.

The square root of 21336331 is about 4619.1266490539. The cubic root of 21336331 is about 277.3574995442.

Adding to 21336331 its reverse (13363312), we get a palindrome (34699643).

It can be divided in two parts, 2133 and 6331, that added together give a square (8464 = 92²).

The spelling of 21336331 in words is "twenty-one million, three hundred thirty-six thousand, three hundred thirty-one".