21146231 has 2 divisors, whose sum is σ = 21146232. Its totient is φ = 21146230.

The previous prime is 21146207. The next prime is 21146243. The reversal of 21146231 is 13264112.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21146231 is a prime.

It is a super-3 number, since 3×21146231³ (a number of 23 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21146261) 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, 10573115 + 10573116.

It is an arithmetic number, because the mean of its divisors is an integer number (10573116).

Almost surely, 2^21146231 is an apocalyptic number.

21146231 is a deficient number, since it is larger than the sum of its proper divisors (1).

21146231 is an equidigital number, since it uses as much as digits as its factorization.

21146231 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 288, while the sum is 20.

The square root of 21146231 is about 4598.5031260183. The cubic root of 21146231 is about 276.5313182907.

The spelling of 21146231 in words is "twenty-one million, one hundred forty-six thousand, two hundred thirty-one".