1691345 has 4 divisors (see below), whose sum is σ = 2029620. Its totient is φ = 1353072.

The previous prime is 1691321. The next prime is 1691359. The reversal of 1691345 is 5431961.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 984064 + 707281 = 992^2 + 841^2 .

It is a cyclic number.

It is not a de Polignac number, because 1691345 - 2¹⁶ = 1625809 is a prime.

It is an Ulam number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 169130 + ... + 169139.

It is an arithmetic number, because the mean of its divisors is an integer number (507405).

2^1691345 is an apocalyptic number.

It is an amenable number.

1691345 is a deficient number, since it is larger than the sum of its proper divisors (338275).

1691345 is an equidigital number, since it uses as much as digits as its factorization.

1691345 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 338274.

The product of its digits is 3240, while the sum is 29.

The square root of 1691345 is about 1300.5172048074. The cubic root of 1691345 is about 119.1454333749.

The spelling of 1691345 in words is "one million, six hundred ninety-one thousand, three hundred forty-five".