21462281 has 2 divisors, whose sum is σ = 21462282. Its totient is φ = 21462280.

The previous prime is 21462269. The next prime is 21462293. The reversal of 21462281 is 18226412.

It is a happy number.

It is a balanced prime because it is at equal distance from previous prime (21462269) and next prime (21462293).

It can be written as a sum of positive squares in only one way, i.e., 13104400 + 8357881 = 3620^2 + 2891^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21462281 is a prime.

It is a super-2 number, since 2×21462281² = 921259011445922, which contains 22 as substring.

It is a Chen prime.

It is equal to p_1357370 and since 21462281 and 1357370 have the same sum of digits, it is a Honaker prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21462281.

It is not a weakly prime, because it can be changed into another prime (21462251) 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, 10731140 + 10731141.

It is an arithmetic number, because the mean of its divisors is an integer number (10731141).

Almost surely, 2^21462281 is an apocalyptic number.

It is an amenable number.

21462281 is a deficient number, since it is larger than the sum of its proper divisors (1).

21462281 is an equidigital number, since it uses as much as digits as its factorization.

21462281 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1536, while the sum is 26.

The square root of 21462281 is about 4632.7401179000. The cubic root of 21462281 is about 277.9021833806.

Adding to 21462281 its reverse (18226412), we get a palindrome (39688693).

The spelling of 21462281 in words is "twenty-one million, four hundred sixty-two thousand, two hundred eighty-one".