21012220012 has 24 divisors (see below), whose sum is σ = 42030406656. Its totient is φ = 9003958608.

The previous prime is 21012219983. The next prime is 21012220013. The reversal of 21012220012 is 21002221012.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 21012219974 and 21012220001.

It is not an unprimeable number, because it can be changed into a prime (21012220013) 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, 162843 + ... + 261805.

It is an arithmetic number, because the mean of its divisors is an integer number (1751266944).

Almost surely, 2^21012220012 is an apocalyptic number.

It is an amenable number.

21012220012 is an abundant number, since it is smaller than the sum of its proper divisors (21018186644).

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

21012220012 is a wasteful number, since it uses less digits than its factorization.

21012220012 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 106557 (or 106555 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 13.

Adding to 21012220012 its reverse (21002221012), we get a palindrome (42014441024).

The spelling of 21012220012 in words is "twenty-one billion, twelve million, two hundred twenty thousand, twelve".