1291328 has 14 divisors (see below), whose sum is σ = 2562606. Its totient is φ = 645632.

The previous prime is 1291327. The next prime is 1291343. The reversal of 1291328 is 8231921.

It can be written as a sum of positive squares in only one way, i.e., 1183744 + 107584 = 1088^2 + 328^2 .

It is a junction number, because it is equal to n+sod(n) for n = 1291297 and 1291306.

It is not an unprimeable number, because it can be changed into a prime (1291321) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10025 + ... + 10152.

2^1291328 is an apocalyptic number.

It is an amenable number.

1291328 is a deficient number, since it is larger than the sum of its proper divisors (1271278).

1291328 is an equidigital number, since it uses as much as digits as its factorization.

1291328 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20189 (or 20179 counting only the distinct ones).

The product of its digits is 864, while the sum is 26.

The square root of 1291328 is about 1136.3661381791. The cubic root of 1291328 is about 108.8960656723.

The spelling of 1291328 in words is "one million, two hundred ninety-one thousand, three hundred twenty-eight".