313211621 has 4 divisors (see below), whose sum is σ = 331635852. Its totient is φ = 294787392.

The previous prime is 313211611. The next prime is 313211627. The reversal of 313211621 is 126112313.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 126112313 = 2437 ⋅51749.

It can be written as a sum of positive squares in 2 ways, for example, as 248409121 + 64802500 = 15761^2 + 8050^2 .

It is a cyclic number.

It is not a de Polignac number, because 313211621 - 2⁶ = 313211557 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 313211593 and 313211602.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (313211627) 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, 9212090 + ... + 9212123.

It is an arithmetic number, because the mean of its divisors is an integer number (82908963).

Almost surely, 2^313211621 is an apocalyptic number.

It is an amenable number.

313211621 is a deficient number, since it is larger than the sum of its proper divisors (18424231).

313211621 is a wasteful number, since it uses less digits than its factorization.

313211621 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18424230.

The product of its digits is 216, while the sum is 20.

The square root of 313211621 is about 17697.7857654566. The cubic root of 313211621 is about 679.1191167349.

Adding to 313211621 its reverse (126112313), we get a palindrome (439323934).

The spelling of 313211621 in words is "three hundred thirteen million, two hundred eleven thousand, six hundred twenty-one".