321521201 has 4 divisors (see below), whose sum is σ = 324052992. Its totient is φ = 318989412.

The previous prime is 321521183. The next prime is 321521227. The reversal of 321521201 is 102125123.

It is a happy number.

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, and also an emirpimes, since its reverse is a distinct semiprime: 102125123 = 251 ⋅406873.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-321521201 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 321521201.

It is not an unprimeable number, because it can be changed into a prime (321521251) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1265705 + ... + 1265958.

It is an arithmetic number, because the mean of its divisors is an integer number (81013248).

Almost surely, 2^321521201 is an apocalyptic number.

It is an amenable number.

321521201 is a deficient number, since it is larger than the sum of its proper divisors (2531791).

321521201 is a wasteful number, since it uses less digits than its factorization.

321521201 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2531790.

The product of its (nonzero) digits is 120, while the sum is 17.

The square root of 321521201 is about 17931.0122692502. The cubic root of 321521201 is about 685.0725062221.

Adding to 321521201 its reverse (102125123), we get a palindrome (423646324).

The spelling of 321521201 in words is "three hundred twenty-one million, five hundred twenty-one thousand, two hundred one".