311012221 has 12 divisors (see below), whose sum is σ = 342308820. Its totient is φ = 282372480.

The previous prime is 311012213. The next prime is 311012227. The reversal of 311012221 is 122210113.

It can be written as a sum of positive squares in 6 ways, for example, as 114704100 + 196308121 = 10710^2 + 14011^2 .

It is not a de Polignac number, because 311012221 - 2³ = 311012213 is a prime.

It is a super-2 number, since 2×311012221² = 193457203222705682, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (13).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (311012227) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 4776 + ... + 25393.

It is an arithmetic number, because the mean of its divisors is an integer number (28525735).

Almost surely, 2^311012221 is an apocalyptic number.

It is an amenable number.

311012221 is a deficient number, since it is larger than the sum of its proper divisors (31296599).

311012221 is a wasteful number, since it uses less digits than its factorization.

311012221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 30256 (or 30243 counting only the distinct ones).

The product of its (nonzero) digits is 24, while the sum is 13.

The square root of 311012221 is about 17635.5385798109. The cubic root of 311012221 is about 677.5257696384.

Adding to 311012221 its reverse (122210113), we get a palindrome (433222334).

The spelling of 311012221 in words is "three hundred eleven million, twelve thousand, two hundred twenty-one".