81022021212 has 24 divisors (see below), whose sum is σ = 206237872512. Its totient is φ = 24552127600.

The previous prime is 81022021211. The next prime is 81022021343. The reversal of 81022021212 is 21212022018.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81022021211) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 306901464 + ... + 306901727.

It is an arithmetic number, because the mean of its divisors is an integer number (8593244688).

Almost surely, 2^81022021212 is an apocalyptic number.

It is an amenable number.

81022021212 is an abundant number, since it is smaller than the sum of its proper divisors (125215851300).

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

81022021212 is a wasteful number, since it uses less digits than its factorization.

81022021212 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 613803209 (or 613803207 counting only the distinct ones).

The product of its (nonzero) digits is 256, while the sum is 21.

It can be divided in two parts, 810 and 22021212, that added together give a palindrome (22022022).

The spelling of 81022021212 in words is "eighty-one billion, twenty-two million, twenty-one thousand, two hundred twelve".