1690042 has 4 divisors (see below), whose sum is σ = 2535066. Its totient is φ = 845020.

The previous prime is 1690019. The next prime is 1690043. The reversal of 1690042 is 2400961.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 2400961 = 17 ⋅141233.

It can be written as a sum of positive squares in only one way, i.e., 1279161 + 410881 = 1131^2 + 641^2 .

It is a Smith number, since the sum of its digits (22) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a pancake number, because a pancake can be divided into 1690042 parts by 1838 straight cuts.

It is a junction number, because it is equal to n+sod(n) for n = 1689995 and 1690022.

It is not an unprimeable number, because it can be changed into a prime (1690043) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 422509 + ... + 422512.

2^1690042 is an apocalyptic number.

1690042 is a deficient number, since it is larger than the sum of its proper divisors (845024).

1690042 is an equidigital number, since it uses as much as digits as its factorization.

1690042 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 845023.

The product of its (nonzero) digits is 432, while the sum is 22.

The square root of 1690042 is about 1300.0161537458. The cubic root of 1690042 is about 119.1148292534.

The spelling of 1690042 in words is "one million, six hundred ninety thousand, forty-two".