67644281 has 2 divisors, whose sum is σ = 67644282. Its totient is φ = 67644280.

The previous prime is 67644259. The next prime is 67644319. The reversal of 67644281 is 18244676.

It is an a-pointer prime, because the next prime (67644319) can be obtained adding 67644281 to its sum of digits (38).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 64000000 + 3644281 = 8000^2 + 1909^2 .

It is a cyclic number.

It is not a de Polignac number, because 67644281 - 2⁶ = 67644217 is a prime.

It is a super-2 number, since 2×67644281² = 9151497504013922, which contains 22 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (67644781) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33822140 + 33822141.

It is an arithmetic number, because the mean of its divisors is an integer number (33822141).

Almost surely, 2^67644281 is an apocalyptic number.

It is an amenable number.

67644281 is a deficient number, since it is larger than the sum of its proper divisors (1).

67644281 is an equidigital number, since it uses as much as digits as its factorization.

67644281 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 64512, while the sum is 38.

The square root of 67644281 is about 8224.6143374629. The cubic root of 67644281 is about 407.4525389165.

The spelling of 67644281 in words is "sixty-seven million, six hundred forty-four thousand, two hundred eighty-one".