311211720 has 80 divisors (see below), whose sum is σ = 1046028060. Its totient is φ = 82988928.

The previous prime is 311211713. The next prime is 311211721. The reversal of 311211720 is 27112113.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 305480484 + 5731236 = 17478^2 + 2394^2 .

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a junction number, because it is equal to n+sod(n) for n = 311211693 and 311211702.

It is not an unprimeable number, because it can be changed into a prime (311211721) 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 19 ways as a sum of consecutive naturals, for example, 44787 + ... + 51266.

Almost surely, 2^311211720 is an apocalyptic number.

311211720 is a gapful number since it is divisible by the number (30) formed by its first and last digit.

It is an amenable number.

311211720 is an abundant number, since it is smaller than the sum of its proper divisors (734816340).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

311211720 is a wasteful number, since it uses less digits than its factorization.

311211720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 96076 (or 96063 counting only the distinct ones).

The product of its (nonzero) digits is 84, while the sum is 18.

The square root of 311211720 is about 17641.1938371529. The cubic root of 311211720 is about 677.6706051293.

Adding to 311211720 its reverse (27112113), we get a palindrome (338323833).

The spelling of 311211720 in words is "three hundred eleven million, two hundred eleven thousand, seven hundred twenty".