67655681 has 2 divisors, whose sum is σ = 67655682. Its totient is φ = 67655680.

The previous prime is 67655659. The next prime is 67655683. The reversal of 67655681 is 18655676.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 65044225 + 2611456 = 8065^2 + 1616^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-67655681 is a prime.

It is a super-2 number, since 2×67655681² = 9154582343147522, which contains 22 as substring.

Together with 67655683, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (67655683) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33827840 + 33827841.

It is an arithmetic number, because the mean of its divisors is an integer number (33827841).

Almost surely, 2^67655681 is an apocalyptic number.

It is an amenable number.

67655681 is a deficient number, since it is larger than the sum of its proper divisors (1).

67655681 is an equidigital number, since it uses as much as digits as its factorization.

67655681 is an evil number, because the sum of its binary digits is even.

The product of its digits is 302400, while the sum is 44.

The square root of 67655681 is about 8225.3073498806. The cubic root of 67655681 is about 407.4754267742.

The spelling of 67655681 in words is "sixty-seven million, six hundred fifty-five thousand, six hundred eighty-one".