31311222012 has 144 divisors (see below), whose sum is σ = 91184970240. Its totient is φ = 8874105984.

The previous prime is 31311221993. The next prime is 31311222043. The reversal of 31311222012 is 21022211313.

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

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 29454993 + ... + 29456055.

It is an arithmetic number, because the mean of its divisors is an integer number (633228960).

Almost surely, 2^31311222012 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 31311222012, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (45592485120).

31311222012 is an abundant number, since it is smaller than the sum of its proper divisors (59873748228).

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

31311222012 is a wasteful number, since it uses less digits than its factorization.

31311222012 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1912 (or 1907 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 18.

Adding to 31311222012 its reverse (21022211313), we get a palindrome (52333433325).

The spelling of 31311222012 in words is "thirty-one billion, three hundred eleven million, two hundred twenty-two thousand, twelve".