313021221 has 16 divisors (see below), whose sum is σ = 453858624. Its totient is φ = 191096064.

The previous prime is 313021213. The next prime is 313021279. The reversal of 313021221 is 122120313.

It is not a de Polignac number, because 313021221 - 2³ = 313021213 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 313021221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (313021201) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 81055 + ... + 84828.

It is an arithmetic number, because the mean of its divisors is an integer number (28366164).

Almost surely, 2^313021221 is an apocalyptic number.

It is an amenable number.

313021221 is a deficient number, since it is larger than the sum of its proper divisors (140837403).

313021221 is a wasteful number, since it uses less digits than its factorization.

313021221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 165940.

The product of its (nonzero) digits is 72, while the sum is 15.

The square root of 313021221 is about 17692.4057437082. The cubic root of 313021221 is about 678.9814776424.

Adding to 313021221 its reverse (122120313), we get a palindrome (435141534).

It can be divided in two parts, 31302 and 1221, that added together give a palindrome (32523).

The spelling of 313021221 in words is "three hundred thirteen million, twenty-one thousand, two hundred twenty-one".