67391971 has 2 divisors, whose sum is σ = 67391972. Its totient is φ = 67391970.

The previous prime is 67391963. The next prime is 67392019. The reversal of 67391971 is 17919376.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 67391971 - 2³ = 67391963 is a prime.

It is not a weakly prime, because it can be changed into another prime (67391671) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33695985 + 33695986.

It is an arithmetic number, because the mean of its divisors is an integer number (33695986).

Almost surely, 2^67391971 is an apocalyptic number.

67391971 is a deficient number, since it is larger than the sum of its proper divisors (1).

67391971 is an equidigital number, since it uses as much as digits as its factorization.

67391971 is an evil number, because the sum of its binary digits is even.

The product of its digits is 71442, while the sum is 43.

The square root of 67391971 is about 8209.2612944162. The cubic root of 67391971 is about 406.9453147897.

The spelling of 67391971 in words is "sixty-seven million, three hundred ninety-one thousand, nine hundred seventy-one".