1606694689 has 2 divisors, whose sum is σ = 1606694690. Its totient is φ = 1606694688.

The previous prime is 1606694651. The next prime is 1606694759. The reversal of 1606694689 is 9864966061.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1540955025 + 65739664 = 39255^2 + 8108^2 .

It is an emirp because it is prime and its reverse (9864966061) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1606694689 is a prime.

It is not a weakly prime, because it can be changed into another prime (1606697689) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 803347344 + 803347345.

It is an arithmetic number, because the mean of its divisors is an integer number (803347345).

Almost surely, 2^1606694689 is an apocalyptic number.

It is an amenable number.

1606694689 is a deficient number, since it is larger than the sum of its proper divisors (1).

1606694689 is an equidigital number, since it uses as much as digits as its factorization.

1606694689 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3359232, while the sum is 55.

The square root of 1606694689 is about 40083.5962583199. The cubic root of 1606694689 is about 1171.2361078147.

The spelling of 1606694689 in words is "one billion, six hundred six million, six hundred ninety-four thousand, six hundred eighty-nine".