312311220 has 96 divisors (see below), whose sum is σ = 944939520. Its totient is φ = 76615680.

The previous prime is 312311183. The next prime is 312311239. The reversal of 312311220 is 22113213.

312311220 is nontrivially palindromic in base 11.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a self number, because there is not a number n which added to its sum of digits gives 312311220.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 335716 + ... + 336644.

It is an arithmetic number, because the mean of its divisors is an integer number (9843120).

Almost surely, 2^312311220 is an apocalyptic number.

312311220 is a gapful number since it is divisible by the number (30) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 312311220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (472469760).

312311220 is an abundant number, since it is smaller than the sum of its proper divisors (632628300).

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

312311220 is a wasteful number, since it uses less digits than its factorization.

312311220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1385 (or 1383 counting only the distinct ones).

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

The square root of 312311220 is about 17672.3292183006. The cubic root of 312311220 is about 678.4677292214.

Adding to 312311220 its reverse (22113213), we get a palindrome (334424433).

The spelling of 312311220 in words is "three hundred twelve million, three hundred eleven thousand, two hundred twenty".