67891381 has 2 divisors, whose sum is σ = 67891382. Its totient is φ = 67891380.

The previous prime is 67891379. The next prime is 67891391. The reversal of 67891381 is 18319876.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 57912100 + 9979281 = 7610^2 + 3159^2 .

It is a cyclic number.

It is not a de Polignac number, because 67891381 - 2¹ = 67891379 is a prime.

It is a super-2 number, since 2×67891381² = 9218479228174322, which contains 22 as substring.

Together with 67891379, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (67891391) 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, 33945690 + 33945691.

It is an arithmetic number, because the mean of its divisors is an integer number (33945691).

Almost surely, 2^67891381 is an apocalyptic number.

It is an amenable number.

67891381 is a deficient number, since it is larger than the sum of its proper divisors (1).

67891381 is an equidigital number, since it uses as much as digits as its factorization.

67891381 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 72576, while the sum is 43.

The square root of 67891381 is about 8239.6226248536. The cubic root of 67891381 is about 407.9480682492.

The spelling of 67891381 in words is "sixty-seven million, eight hundred ninety-one thousand, three hundred eighty-one".