1321745 has 4 divisors (see below), whose sum is σ = 1586100. Its totient is φ = 1057392.

The previous prime is 1321729. The next prime is 1321753. The reversal of 1321745 is 5471231.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 5471231 = 107 ⋅51133.

It can be written as a sum of positive squares in 2 ways, for example, as 146689 + 1175056 = 383^2 + 1084^2 .

It is a cyclic number.

It is not a de Polignac number, because 1321745 - 2⁴ = 1321729 is a prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 1321745.

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, 132170 + ... + 132179.

It is an arithmetic number, because the mean of its divisors is an integer number (396525).

2^1321745 is an apocalyptic number.

It is an amenable number.

1321745 is a deficient number, since it is larger than the sum of its proper divisors (264355).

1321745 is an equidigital number, since it uses as much as digits as its factorization.

1321745 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 264354.

The product of its digits is 840, while the sum is 23.

The square root of 1321745 is about 1149.6716922670. The cubic root of 1321745 is about 109.7444480841.

Adding to 1321745 its reverse (5471231), we get a palindrome (6792976).

The spelling of 1321745 in words is "one million, three hundred twenty-one thousand, seven hundred forty-five".