21282361 has 2 divisors, whose sum is σ = 21282362. Its totient is φ = 21282360.

The previous prime is 21282353. The next prime is 21282379. The reversal of 21282361 is 16328212.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20611600 + 670761 = 4540^2 + 819^2 .

It is a cyclic number.

It is not a de Polignac number, because 21282361 - 2³ = 21282353 is a prime.

It is not a weakly prime, because it can be changed into another prime (21282301) 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, 10641180 + 10641181.

It is an arithmetic number, because the mean of its divisors is an integer number (10641181).

Almost surely, 2^21282361 is an apocalyptic number.

It is an amenable number.

21282361 is a deficient number, since it is larger than the sum of its proper divisors (1).

21282361 is an equidigital number, since it uses as much as digits as its factorization.

21282361 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1152, while the sum is 25.

The square root of 21282361 is about 4613.2809366003. The cubic root of 21282361 is about 277.1234445684.

It can be divided in two parts, 2128 and 2361, that added together give a square (4489 = 67²).

The spelling of 21282361 in words is "twenty-one million, two hundred eighty-two thousand, three hundred sixty-one".