67664281 has 2 divisors, whose sum is σ = 67664282. Its totient is φ = 67664280.

The previous prime is 67664273. The next prime is 67664293. The reversal of 67664281 is 18246676.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 66015625 + 1648656 = 8125^2 + 1284^2 .

It is a cyclic number.

It is not a de Polignac number, because 67664281 - 2³ = 67664273 is a prime.

It is a super-2 number, since 2×67664281² = 9156909846493922, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (67664381) 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, 33832140 + 33832141.

It is an arithmetic number, because the mean of its divisors is an integer number (33832141).

Almost surely, 2^67664281 is an apocalyptic number.

It is an amenable number.

67664281 is a deficient number, since it is larger than the sum of its proper divisors (1).

67664281 is an equidigital number, since it uses as much as digits as its factorization.

67664281 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 96768, while the sum is 40.

The square root of 67664281 is about 8225.8301100862. The cubic root of 67664281 is about 407.4926913515.

The spelling of 67664281 in words is "sixty-seven million, six hundred sixty-four thousand, two hundred eighty-one".