67406681 has 2 divisors, whose sum is σ = 67406682. Its totient is φ = 67406680.

The previous prime is 67406663. The next prime is 67406687. The reversal of 67406681 is 18660476.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 49632025 + 17774656 = 7045^2 + 4216^2 .

It is a cyclic number.

It is not a de Polignac number, because 67406681 - 2²² = 63212377 is a prime.

It is a super-2 number, since 2×67406681² = 9087321286871522, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (67406687) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33703340 + 33703341.

It is an arithmetic number, because the mean of its divisors is an integer number (33703341).

Almost surely, 2^67406681 is an apocalyptic number.

It is an amenable number.

67406681 is a deficient number, since it is larger than the sum of its proper divisors (1).

67406681 is an equidigital number, since it uses as much as digits as its factorization.

67406681 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 48384, while the sum is 38.

The square root of 67406681 is about 8210.1571848534. The cubic root of 67406681 is about 406.9749213338.

The spelling of 67406681 in words is "sixty-seven million, four hundred six thousand, six hundred eighty-one".