321012661 has 4 divisors (see below), whose sum is σ = 321084172. Its totient is φ = 320941152.

The previous prime is 321012647. The next prime is 321012701. The reversal of 321012661 is 166210123.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 90155025 + 230857636 = 9495^2 + 15194^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-321012661 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 (321012761) 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, 28536 + ... + 38161.

It is an arithmetic number, because the mean of its divisors is an integer number (80271043).

Almost surely, 2^321012661 is an apocalyptic number.

It is an amenable number.

321012661 is a deficient number, since it is larger than the sum of its proper divisors (71511).

321012661 is an equidigital number, since it uses as much as digits as its factorization.

321012661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 71510.

The product of its (nonzero) digits is 432, while the sum is 22.

The square root of 321012661 is about 17916.8261977394. The cubic root of 321012661 is about 684.7111297299.

Adding to 321012661 its reverse (166210123), we get a palindrome (487222784).

The spelling of 321012661 in words is "three hundred twenty-one million, twelve thousand, six hundred sixty-one".