321621609 has 8 divisors (see below), whose sum is σ = 431006400. Its totient is φ = 213325616.

The previous prime is 321621539. The next prime is 321621631. The reversal of 321621609 is 906126123.

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 321621609 - 2²⁵ = 288067177 is a prime.

It is not an unprimeable number, because it can be changed into a prime (321621659) 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, 271509 + ... + 272690.

It is an arithmetic number, because the mean of its divisors is an integer number (53875800).

Almost surely, 2^321621609 is an apocalyptic number.

It is an amenable number.

321621609 is a deficient number, since it is larger than the sum of its proper divisors (109384791).

321621609 is a wasteful number, since it uses less digits than its factorization.

321621609 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 544399.

The product of its (nonzero) digits is 3888, while the sum is 30.

The square root of 321621609 is about 17933.8118926234. The cubic root of 321621609 is about 685.1438126665.

The spelling of 321621609 in words is "three hundred twenty-one million, six hundred twenty-one thousand, six hundred nine".