66644867 has 2 divisors, whose sum is σ = 66644868. Its totient is φ = 66644866.

The previous prime is 66644861. The next prime is 66644873. The reversal of 66644867 is 76844666.

It is a balanced prime because it is at equal distance from previous prime (66644861) and next prime (66644873).

It is a cyclic number.

It is not a de Polignac number, because 66644867 - 2²⁰ = 65596291 is a prime.

It is not a weakly prime, because it can be changed into another prime (66644861) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33322433 + 33322434.

It is an arithmetic number, because the mean of its divisors is an integer number (33322434).

Almost surely, 2^66644867 is an apocalyptic number.

66644867 is a deficient number, since it is larger than the sum of its proper divisors (1).

66644867 is an equidigital number, since it uses as much as digits as its factorization.

66644867 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1161216, while the sum is 47.

The square root of 66644867 is about 8163.6307486314. The cubic root of 66644867 is about 405.4359315613.

The spelling of 66644867 in words is "sixty-six million, six hundred forty-four thousand, eight hundred sixty-seven".