21714281 has 2 divisors, whose sum is σ = 21714282. Its totient is φ = 21714280.

The previous prime is 21714271. The next prime is 21714313. The reversal of 21714281 is 18241712.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20976400 + 737881 = 4580^2 + 859^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21714281 is a prime.

It is a super-2 number, since 2×21714281² = 943019998693922, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 21714281.

It is not a weakly prime, because it can be changed into another prime (21714271) 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, 10857140 + 10857141.

It is an arithmetic number, because the mean of its divisors is an integer number (10857141).

Almost surely, 2^21714281 is an apocalyptic number.

It is an amenable number.

21714281 is a deficient number, since it is larger than the sum of its proper divisors (1).

21714281 is an equidigital number, since it uses as much as digits as its factorization.

21714281 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 896, while the sum is 26.

The square root of 21714281 is about 4659.8584742458. The cubic root of 21714281 is about 278.9856195189.

Adding to 21714281 its reverse (18241712), we get a palindrome (39955993).

The spelling of 21714281 in words is "twenty-one million, seven hundred fourteen thousand, two hundred eighty-one".