1690664 has 8 divisors (see below), whose sum is σ = 3170010. Its totient is φ = 845328.

The previous prime is 1690651. The next prime is 1690669. The reversal of 1690664 is 4660961.

It can be written as a sum of positive squares in only one way, i.e., 1562500 + 128164 = 1250^2 + 358^2 .

It is a tau number, because it is divible by the number of its divisors (8).

It is a self number, because there is not a number n which added to its sum of digits gives 1690664.

It is not an unprimeable number, because it can be changed into a prime (1690669) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 105659 + ... + 105674.

2^1690664 is an apocalyptic number.

It is an amenable number.

1690664 is a deficient number, since it is larger than the sum of its proper divisors (1479346).

1690664 is a wasteful number, since it uses less digits than its factorization.

1690664 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 211339 (or 211335 counting only the distinct ones).

The product of its (nonzero) digits is 7776, while the sum is 32.

The square root of 1690664 is about 1300.2553595352. The cubic root of 1690664 is about 119.1294403964.

The spelling of 1690664 in words is "one million, six hundred ninety thousand, six hundred sixty-four".