321010021 has 4 divisors (see below), whose sum is σ = 321047500. Its totient is φ = 320972544.

The previous prime is 321010009. The next prime is 321010049. The reversal of 321010021 is 120010123.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 120010123 = 17 ⋅7059419.

It can be written as a sum of positive squares in 2 ways, for example, as 57304900 + 263705121 = 7570^2 + 16239^2 .

It is a cyclic number.

It is not a de Polignac number, because 321010021 - 2⁵ = 321009989 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (321010321) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1135 + ... + 25363.

It is an arithmetic number, because the mean of its divisors is an integer number (80261875).

Almost surely, 2^321010021 is an apocalyptic number.

It is an amenable number.

321010021 is a deficient number, since it is larger than the sum of its proper divisors (37479).

321010021 is a wasteful number, since it uses less digits than its factorization.

321010021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 37478.

The product of its (nonzero) digits is 12, while the sum is 10.

The square root of 321010021 is about 17916.7525238253. The cubic root of 321010021 is about 684.7092527091.

Adding to 321010021 its reverse (120010123), we get a palindrome (441020144).

It can be divided in two parts, 3210 and 10021, that added together give a palindrome (13231).

The spelling of 321010021 in words is "three hundred twenty-one million, ten thousand, twenty-one".