1321621 has 12 divisors (see below), whose sum is σ = 1597152. Its totient is φ = 1071144.

The previous prime is 1321601. The next prime is 1321627. The reversal of 1321621 is 1261231.

It is not a de Polignac number, because 1321621 - 2⁵ = 1321589 is a prime.

It is a Duffinian number.

It is a zygodrome in base 4.

It is a junction number, because it is equal to n+sod(n) for n = 1321595 and 1321604.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1321627) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2266 + ... + 2788.

It is an arithmetic number, because the mean of its divisors is an integer number (133096).

2^1321621 is an apocalyptic number.

It is an amenable number.

1321621 is a deficient number, since it is larger than the sum of its proper divisors (275531).

1321621 is an equidigital number, since it uses as much as digits as its factorization.

1321621 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 568 (or 549 counting only the distinct ones).

The product of its digits is 72, while the sum is 16.

The square root of 1321621 is about 1149.6177625628. The cubic root of 1321621 is about 109.7410160713.

Adding to 1321621 its reverse (1261231), we get a palindrome (2582852).

The spelling of 1321621 in words is "one million, three hundred twenty-one thousand, six hundred twenty-one".