311812921728 has 384 divisors, whose sum is σ = 1144709280000. Its totient is φ = 79105904640.

The previous prime is 311812921727. The next prime is 311812921759. The reversal of 311812921728 is 827129218113.

311812921728 is a `hidden beast` number, since 311 + 81 + 2 + 92 + 172 + 8 = 666.

It is a tau number, because it is divible by the number of its divisors (384).

It is a nude number because it is divisible by every one of its digits.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (311812921723) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 3773398 + ... + 3855146.

It is an arithmetic number, because the mean of its divisors is an integer number (2981013750).

Almost surely, 2^311812921728 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 311812921728, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (572354640000).

311812921728 is an abundant number, since it is smaller than the sum of its proper divisors (832896358272).

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

311812921728 is a wasteful number, since it uses less digits than its factorization.

311812921728 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 81830 (or 81815 counting only the distinct ones).

The product of its digits is 96768, while the sum is 45.

The spelling of 311812921728 in words is "three hundred eleven billion, eight hundred twelve million, nine hundred twenty-one thousand, seven hundred twenty-eight".