66381967 has 2 divisors, whose sum is σ = 66381968. Its totient is φ = 66381966.

The previous prime is 66381961. The next prime is 66382007. The reversal of 66381967 is 76918366.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 66381967 - 2¹¹ = 66379919 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66381961) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33190983 + 33190984.

It is an arithmetic number, because the mean of its divisors is an integer number (33190984).

Almost surely, 2^66381967 is an apocalyptic number.

66381967 is a deficient number, since it is larger than the sum of its proper divisors (1).

66381967 is an equidigital number, since it uses as much as digits as its factorization.

66381967 is an evil number, because the sum of its binary digits is even.

The product of its digits is 326592, while the sum is 46.

The square root of 66381967 is about 8147.5129334049. The cubic root of 66381967 is about 404.9021091461.

The spelling of 66381967 in words is "sixty-six million, three hundred eighty-one thousand, nine hundred sixty-seven".