1321655 has 4 divisors (see below), whose sum is σ = 1585992. Its totient is φ = 1057320.

The previous prime is 1321651. The next prime is 1321657. The reversal of 1321655 is 5561231.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 5561231 = 13 ⋅427787.

It is not a de Polignac number, because 1321655 - 2² = 1321651 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 1321655.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1321651) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 132161 + ... + 132170.

It is an arithmetic number, because the mean of its divisors is an integer number (396498).

2^1321655 is an apocalyptic number.

1321655 is a deficient number, since it is larger than the sum of its proper divisors (264337).

1321655 is an equidigital number, since it uses as much as digits as its factorization.

1321655 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 264336.

The product of its digits is 900, while the sum is 23.

The square root of 1321655 is about 1149.6325499915. The cubic root of 1321655 is about 109.7419571284.

Adding to 1321655 its reverse (5561231), we get a palindrome (6882886).

The spelling of 1321655 in words is "one million, three hundred twenty-one thousand, six hundred fifty-five".