21283147 has 2 divisors, whose sum is σ = 21283148. Its totient is φ = 21283146.

The previous prime is 21283139. The next prime is 21283169. The reversal of 21283147 is 74138212.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21283147 - 2³ = 21283139 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (21283117) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10641573 + 10641574.

It is an arithmetic number, because the mean of its divisors is an integer number (10641574).

Almost surely, 2^21283147 is an apocalyptic number.

21283147 is a deficient number, since it is larger than the sum of its proper divisors (1).

21283147 is an equidigital number, since it uses as much as digits as its factorization.

21283147 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2688, while the sum is 28.

The square root of 21283147 is about 4613.3661246426. The cubic root of 21283147 is about 277.1268561001.

It can be divided in two parts, 212831 and 47, that added together give a triangular number (212878 = T₆₅₂).

The spelling of 21283147 in words is "twenty-one million, two hundred eighty-three thousand, one hundred forty-seven".