313216621 has 4 divisors (see below), whose sum is σ = 313311292. Its totient is φ = 313121952.

The previous prime is 313216583. The next prime is 313216627. The reversal of 313216621 is 126612313.

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 49154121 + 264062500 = 7011^2 + 16250^2 .

It is a cyclic number.

It is not a de Polignac number, because 313216621 - 2²¹ = 311119469 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 (313216627) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 42186 + ... + 49051.

It is an arithmetic number, because the mean of its divisors is an integer number (78327823).

Almost surely, 2^313216621 is an apocalyptic number.

It is an amenable number.

313216621 is a deficient number, since it is larger than the sum of its proper divisors (94671).

313216621 is an equidigital number, since it uses as much as digits as its factorization.

313216621 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 94670.

The product of its digits is 1296, while the sum is 25.

The square root of 313216621 is about 17697.9270255022. The cubic root of 313216621 is about 679.1227304551.

Adding to 313216621 its reverse (126612313), we get a palindrome (439828934).

The spelling of 313216621 in words is "three hundred thirteen million, two hundred sixteen thousand, six hundred twenty-one".