66774689 has 4 divisors (see below), whose sum is σ = 66810900. Its totient is φ = 66738480.

The previous prime is 66774661. The next prime is 66774707. The reversal of 66774689 is 98647766.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 62331025 + 4443664 = 7895^2 + 2108^2 .

It is a cyclic number.

It is not a de Polignac number, because 66774689 - 2¹² = 66770593 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 66774689.

It is not an unprimeable number, because it can be changed into a prime (66774619) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 15182 + ... + 19079.

It is an arithmetic number, because the mean of its divisors is an integer number (16702725).

Almost surely, 2^66774689 is an apocalyptic number.

It is an amenable number.

66774689 is a deficient number, since it is larger than the sum of its proper divisors (36211).

66774689 is a wasteful number, since it uses less digits than its factorization.

66774689 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 36210.

The product of its digits is 3048192, while the sum is 53.

The square root of 66774689 is about 8171.5781217584. The cubic root of 66774689 is about 405.6990194081.

The spelling of 66774689 in words is "sixty-six million, seven hundred seventy-four thousand, six hundred eighty-nine".