21052331 has 2 divisors, whose sum is σ = 21052332. Its totient is φ = 21052330.

The previous prime is 21052301. The next prime is 21052333. The reversal of 21052331 is 13325012.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21052331 - 2⁶ = 21052267 is a prime.

It is a super-2 number, since 2×21052331² = 886401281067122, which contains 22 as substring.

Together with 21052333, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (21052333) 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 as a sum of consecutive naturals, namely, 10526165 + 10526166.

It is an arithmetic number, because the mean of its divisors is an integer number (10526166).

Almost surely, 2^21052331 is an apocalyptic number.

21052331 is a deficient number, since it is larger than the sum of its proper divisors (1).

21052331 is an equidigital number, since it uses as much as digits as its factorization.

21052331 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 180, while the sum is 17.

The square root of 21052331 is about 4588.2819224629. The cubic root of 21052331 is about 276.1213977964.

Adding to 21052331 its reverse (13325012), we get a palindrome (34377343).

The spelling of 21052331 in words is "twenty-one million, fifty-two thousand, three hundred thirty-one".