1328881 has 4 divisors (see below), whose sum is σ = 1331200. Its totient is φ = 1326564.

The previous prime is 1328863. The next prime is 1328891. The reversal of 1328881 is 1888231.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1328881 is a prime.

It is a super-2 number, since 2×1328881² = 3531849424322, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1328861) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 400 + ... + 1678.

It is an arithmetic number, because the mean of its divisors is an integer number (332800).

2^1328881 is an apocalyptic number.

It is an amenable number.

1328881 is a deficient number, since it is larger than the sum of its proper divisors (2319).

1328881 is a wasteful number, since it uses less digits than its factorization.

1328881 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2318.

The product of its digits is 3072, while the sum is 31.

The square root of 1328881 is about 1152.7710093509. The cubic root of 1328881 is about 109.9415943387.

It can be divided in two parts, 1328 and 881, that added together give a square (2209 = 47²).

The spelling of 1328881 in words is "one million, three hundred twenty-eight thousand, eight hundred eighty-one".