66189779 has 2 divisors, whose sum is σ = 66189780. Its totient is φ = 66189778.

The previous prime is 66189751. The next prime is 66189811. The reversal of 66189779 is 97798166.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 66189779 - 2²⁰ = 65141203 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 66189779.

It is not a weakly prime, because it can be changed into another prime (66189719) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33094889 + 33094890.

It is an arithmetic number, because the mean of its divisors is an integer number (33094890).

Almost surely, 2^66189779 is an apocalyptic number.

66189779 is a deficient number, since it is larger than the sum of its proper divisors (1).

66189779 is an equidigital number, since it uses as much as digits as its factorization.

66189779 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1143072, while the sum is 53.

The square root of 66189779 is about 8135.7101103714. The cubic root of 66189779 is about 404.5109760840.

The spelling of 66189779 in words is "sixty-six million, one hundred eighty-nine thousand, seven hundred seventy-nine".