31220212212 has 144 divisors (see below), whose sum is σ = 95090063040. Its totient is φ = 8831592000.

The previous prime is 31220212211. The next prime is 31220212223. The reversal of 31220212212 is 21221202213.

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 (31220212211) by changing a digit.

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, 505287 + ... + 563697.

It is an arithmetic number, because the mean of its divisors is an integer number (660347660).

Almost surely, 2^31220212212 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 31220212212, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (47545031520).

31220212212 is an abundant number, since it is smaller than the sum of its proper divisors (63869850828).

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

31220212212 is a wasteful number, since it uses less digits than its factorization.

31220212212 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 58539 (or 58524 counting only the distinct ones).

The product of its (nonzero) digits is 192, while the sum is 18.

Adding to 31220212212 its reverse (21221202213), we get a palindrome (52441414425).

Subtracting from 31220212212 its reverse (21221202213), we obtain a palindrome (9999009999).

The spelling of 31220212212 in words is "thirty-one billion, two hundred twenty million, two hundred twelve thousand, two hundred twelve".