66764387 has 2 divisors, whose sum is σ = 66764388. Its totient is φ = 66764386.

The previous prime is 66764371. The next prime is 66764449. The reversal of 66764387 is 78346766.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 66764387 - 2⁴ = 66764371 is a prime.

It is not a weakly prime, because it can be changed into another prime (66764987) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33382193 + 33382194.

It is an arithmetic number, because the mean of its divisors is an integer number (33382194).

Almost surely, 2^66764387 is an apocalyptic number.

66764387 is a deficient number, since it is larger than the sum of its proper divisors (1).

66764387 is an equidigital number, since it uses as much as digits as its factorization.

66764387 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1016064, while the sum is 47.

The square root of 66764387 is about 8170.9477418473. The cubic root of 66764387 is about 405.6781545849.

The spelling of 66764387 in words is "sixty-six million, seven hundred sixty-four thousand, three hundred eighty-seven".