31001221212 has 72 divisors (see below), whose sum is σ = 80679698736. Its totient is φ = 9209872896.

The previous prime is 31001221211. The next prime is 31001221333. The reversal of 31001221212 is 21212210013.

It is a super-2 number, since 2×31001221212² (a number of 22 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 31001221191 and 31001221200.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31001221211) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 13048 + ... + 249344.

Almost surely, 2^31001221212 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 31001221212, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (40339849368).

31001221212 is an abundant number, since it is smaller than the sum of its proper divisors (49678477524).

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

31001221212 is a wasteful number, since it uses less digits than its factorization.

31001221212 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 236375 (or 236344 counting only the distinct ones).

The product of its (nonzero) digits is 48, while the sum is 15.

Adding to 31001221212 its reverse (21212210013), we get a palindrome (52213431225).

The spelling of 31001221212 in words is "thirty-one billion, one million, two hundred twenty-one thousand, two hundred twelve".