1328691 has 32 divisors (see below), whose sum is σ = 2265088. Its totient is φ = 673920.

The previous prime is 1328683. The next prime is 1328699. The reversal of 1328691 is 1968231.

It is an interprime number because it is at equal distance from previous prime (1328683) and next prime (1328699).

It is not a de Polignac number, because 1328691 - 2³ = 1328683 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1328699) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 8385 + ... + 8541.

It is an arithmetic number, because the mean of its divisors is an integer number (70784).

2^1328691 is an apocalyptic number.

1328691 is a deficient number, since it is larger than the sum of its proper divisors (936397).

1328691 is a wasteful number, since it uses less digits than its factorization.

1328691 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 211.

The product of its digits is 2592, while the sum is 30.

The square root of 1328691 is about 1152.6885962826. The cubic root of 1328691 is about 109.9363543665.

It can be divided in two parts, 132869 and 1, that added together give a triangular number (132870 = T₅₁₅).

The spelling of 1328691 in words is "one million, three hundred twenty-eight thousand, six hundred ninety-one".