31031212320 has 192 divisors, whose sum is σ = 110920803840. Its totient is φ = 8098873344.

The previous prime is 31031212291. The next prime is 31031212321. The reversal of 31031212320 is 2321213013.

31031212320 is a `hidden beast` number, since 31 + 0 + 312 + 1 + 2 + 320 = 666.

It is a super-2 number, since 2×31031212320² (a number of 22 digits) contains 22 as substring.

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 = 31031212293 and 31031212302.

It is not an unprimeable number, because it can be changed into a prime (31031212321) by changing a digit.

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, 126624 + ... + 279456.

It is an arithmetic number, because the mean of its divisors is an integer number (577712520).

Almost surely, 2^31031212320 is an apocalyptic number.

31031212320 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 31031212320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (55460401920).

31031212320 is an abundant number, since it is smaller than the sum of its proper divisors (79889591520).

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

31031212320 is a wasteful number, since it uses less digits than its factorization.

31031212320 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 152904 (or 152890 counting only the distinct ones).

The product of its (nonzero) digits is 216, while the sum is 18.

Adding to 31031212320 its reverse (2321213013), we get a palindrome (33352425333).

The spelling of 31031212320 in words is "thirty-one billion, thirty-one million, two hundred twelve thousand, three hundred twenty".