31221011001312 has 72 divisors (see below), whose sum is σ = 96856090957080. Its totient is φ = 9460912423680.

The previous prime is 31221011001269. The next prime is 31221011001319. The reversal of 31221011001312 is 21310011012213.

31221011001312 is a `hidden beast` number, since 31 + 2 + 210 + 110 + 0 + 1 + 312 = 666.

It is a tau number, because it is divible by the number of its divisors (72).

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31221011001319) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 4927555387 + ... + 4927561722.

It is an arithmetic number, because the mean of its divisors is an integer number (1345223485515).

Almost surely, 2^{31221011001312} is an apocalyptic number.

31221011001312 is a gapful number since it is divisible by the number (32) formed by its first and last digit.

It is an amenable number.

31221011001312 is an abundant number, since it is smaller than the sum of its proper divisors (65635079955768).

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

31221011001312 is a wasteful number, since it uses less digits than its factorization.

31221011001312 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9855117136 (or 9855117125 counting only the distinct ones).

The product of its (nonzero) digits is 72, while the sum is 18.

Adding to 31221011001312 its reverse (21310011012213), we get a palindrome (52531022013525).

The spelling of 31221011001312 in words is "thirty-one trillion, two hundred twenty-one billion, eleven million, one thousand, three hundred twelve".