1690138 has 4 divisors (see below), whose sum is σ = 2535210. Its totient is φ = 845068.

The previous prime is 1690121. The next prime is 1690153. The reversal of 1690138 is 8310961.

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 only one way, i.e., 1456849 + 233289 = 1207^2 + 483^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 422533 + ... + 422536.

2^1690138 is an apocalyptic number.

1690138 is a deficient number, since it is larger than the sum of its proper divisors (845072).

1690138 is an equidigital number, since it uses as much as digits as its factorization.

1690138 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 845071.

The product of its (nonzero) digits is 1296, while the sum is 28.

The square root of 1690138 is about 1300.0530758396. The cubic root of 1690138 is about 119.1170845833.

The spelling of 1690138 in words is "one million, six hundred ninety thousand, one hundred thirty-eight".