1328561 has 4 divisors (see below), whose sum is σ = 1430772. Its totient is φ = 1226352.

The previous prime is 1328539. The next prime is 1328563. The reversal of 1328561 is 1658231.

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 616225 + 712336 = 785^2 + 844^2 .

It is a cyclic number.

It is not a de Polignac number, because 1328561 - 2⁶ = 1328497 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1328561.

It is not an unprimeable number, because it can be changed into a prime (1328563) 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, 51086 + ... + 51111.

It is an arithmetic number, because the mean of its divisors is an integer number (357693).

2^1328561 is an apocalyptic number.

It is an amenable number.

1328561 is a deficient number, since it is larger than the sum of its proper divisors (102211).

1328561 is a wasteful number, since it uses less digits than its factorization.

1328561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 102210.

The product of its digits is 1440, while the sum is 26.

The square root of 1328561 is about 1152.6322049986. The cubic root of 1328561 is about 109.9327688345.

It can be divided in two parts, 13 and 28561, that multiplied together give a 5-th power (371293 = 13⁵).

The spelling of 1328561 in words is "one million, three hundred twenty-eight thousand, five hundred sixty-one".