67728691 has 2 divisors, whose sum is σ = 67728692. Its totient is φ = 67728690.

The previous prime is 67728667. The next prime is 67728779. The reversal of 67728691 is 19682776.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 67728691 - 2¹⁷ = 67597619 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (67728631) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33864345 + 33864346.

It is an arithmetic number, because the mean of its divisors is an integer number (33864346).

Almost surely, 2^67728691 is an apocalyptic number.

67728691 is a deficient number, since it is larger than the sum of its proper divisors (1).

67728691 is an equidigital number, since it uses as much as digits as its factorization.

67728691 is an evil number, because the sum of its binary digits is even.

The product of its digits is 254016, while the sum is 46.

The square root of 67728691 is about 8229.7442852132. The cubic root of 67728691 is about 407.6219485222.

The spelling of 67728691 in words is "sixty-seven million, seven hundred twenty-eight thousand, six hundred ninety-one".