321921409 has 8 divisors (see below), whose sum is σ = 336107520. Its totient is φ = 307751136.

The previous prime is 321921361. The next prime is 321921449. The reversal of 321921409 is 904129123.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 321921409 - 2¹³ = 321913217 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (321921449) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 59197 + ... + 64405.

It is an arithmetic number, because the mean of its divisors is an integer number (42013440).

Almost surely, 2^321921409 is an apocalyptic number.

It is an amenable number.

321921409 is a deficient number, since it is larger than the sum of its proper divisors (14186111).

321921409 is a wasteful number, since it uses less digits than its factorization.

321921409 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7919.

The product of its (nonzero) digits is 3888, while the sum is 31.

The square root of 321921409 is about 17942.1684586897. The cubic root of 321921409 is about 685.3566324514.

The spelling of 321921409 in words is "three hundred twenty-one million, nine hundred twenty-one thousand, four hundred nine".