1321921 has 4 divisors (see below), whose sum is σ = 1332144. Its totient is φ = 1311700.

The previous prime is 1321919. The next prime is 1321927. The reversal of 1321921 is 1291231.

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 1321921 - 2¹ = 1321919 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1321927) 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, 4915 + ... + 5176.

It is an arithmetic number, because the mean of its divisors is an integer number (333036).

2^1321921 is an apocalyptic number.

It is an amenable number.

1321921 is a deficient number, since it is larger than the sum of its proper divisors (10223).

1321921 is a wasteful number, since it uses less digits than its factorization.

1321921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10222.

The product of its digits is 108, while the sum is 19.

The square root of 1321921 is about 1149.7482333102. The cubic root of 1321921 is about 109.7493189595.

The spelling of 1321921 in words is "one million, three hundred twenty-one thousand, nine hundred twenty-one".