1690044605 has 8 divisors (see below), whose sum is σ = 2028278232. Its totient is φ = 1351885888.

The previous prime is 1690044599. The next prime is 1690044739. The reversal of 1690044605 is 5064400961.

It can be written as a sum of positive squares in 4 ways, for example, as 801229636 + 888814969 = 28306^2 + 29813^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1690044605 - 2²⁴ = 1673267389 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 64727 + ... + 87003.

It is an arithmetic number, because the mean of its divisors is an integer number (253534779).

Almost surely, 2^1690044605 is an apocalyptic number.

It is an amenable number.

1690044605 is a deficient number, since it is larger than the sum of its proper divisors (338233627).

1690044605 is a wasteful number, since it uses less digits than its factorization.

1690044605 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 37455.

The product of its (nonzero) digits is 25920, while the sum is 35.

The square root of 1690044605 is about 41110.1520916671. The cubic root of 1690044605 is about 1191.1489045381.

The spelling of 1690044605 in words is "one billion, six hundred ninety million, forty-four thousand, six hundred five".