221031321212 has 96 divisors (see below), whose sum is σ = 446796607488. Its totient is φ = 94877443584.

The previous prime is 221031321197. The next prime is 221031321289. The reversal of 221031321212 is 212123130122.

It is a super-2 number, since 2×221031321212² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 11458808 + ... + 11478080.

It is an arithmetic number, because the mean of its divisors is an integer number (4654131328).

Almost surely, 2^221031321212 is an apocalyptic number.

It is an amenable number.

221031321212 is an abundant number, since it is smaller than the sum of its proper divisors (225765286276).

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

221031321212 is a wasteful number, since it uses less digits than its factorization.

221031321212 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19579 (or 19577 counting only the distinct ones).

The product of its (nonzero) digits is 288, while the sum is 20.

Adding to 221031321212 its reverse (212123130122), we get a palindrome (433154451334).

The spelling of 221031321212 in words is "two hundred twenty-one billion, thirty-one million, three hundred twenty-one thousand, two hundred twelve".