1320621 has 4 divisors (see below), whose sum is σ = 1760832. Its totient is φ = 880412.

The previous prime is 1320617. The next prime is 1320623. The reversal of 1320621 is 1260231.

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.

It is a cyclic number.

It is not a de Polignac number, because 1320621 - 2² = 1320617 is a prime.

It is a D-number.

It is a self number, because there is not a number n which added to its sum of digits gives 1320621.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1320623) 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, 220101 + ... + 220106.

It is an arithmetic number, because the mean of its divisors is an integer number (440208).

2^1320621 is an apocalyptic number.

It is an amenable number.

1320621 is a deficient number, since it is larger than the sum of its proper divisors (440211).

1320621 is an equidigital number, since it uses as much as digits as its factorization.

1320621 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 440210.

The product of its (nonzero) digits is 72, while the sum is 15.

The square root of 1320621 is about 1149.1827530902. The cubic root of 1320621 is about 109.7133306995.

Adding to 1320621 its reverse (1260231), we get a palindrome (2580852).

The spelling of 1320621 in words is "one million, three hundred twenty thousand, six hundred twenty-one".