311228640 has 144 divisors (see below), whose sum is σ = 1108362528. Its totient is φ = 79377408.

The previous prime is 311228627. The next prime is 311228657. The reversal of 311228640 is 46822113.

311228640 is a `hidden beast` number, since 3 + 1 + 12 + 2 + 8 + 640 = 666.

It is a tau number, because it is divible by the number of its divisors (144).

It is a congruent number.

It is an unprimeable number.

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 23 ways as a sum of consecutive naturals, for example, 28422 + ... + 37818.

It is an arithmetic number, because the mean of its divisors is an integer number (7696962).

Almost surely, 2^311228640 is an apocalyptic number.

311228640 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 311228640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (554181264).

311228640 is an abundant number, since it is smaller than the sum of its proper divisors (797133888).

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

311228640 is a wasteful number, since it uses less digits than its factorization.

311228640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9441 (or 9430 counting only the distinct ones).

The product of its (nonzero) digits is 2304, while the sum is 27.

The square root of 311228640 is about 17641.6733900160. The cubic root of 311228640 is about 677.6828861351.

The spelling of 311228640 in words is "three hundred eleven million, two hundred twenty-eight thousand, six hundred forty".