21283771 has 2 divisors, whose sum is σ = 21283772. Its totient is φ = 21283770.

The previous prime is 21283751. The next prime is 21283777. The reversal of 21283771 is 17738212.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21283771 - 2⁵ = 21283739 is a prime.

It is not a weakly prime, because it can be changed into another prime (21283777) 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, 10641885 + 10641886.

It is an arithmetic number, because the mean of its divisors is an integer number (10641886).

Almost surely, 2^21283771 is an apocalyptic number.

21283771 is a deficient number, since it is larger than the sum of its proper divisors (1).

21283771 is an equidigital number, since it uses as much as digits as its factorization.

21283771 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 4704, while the sum is 31.

The square root of 21283771 is about 4613.4337537240. The cubic root of 21283771 is about 277.1295644319.

The spelling of 21283771 in words is "twenty-one million, two hundred eighty-three thousand, seven hundred seventy-one".