21122220012 has 12 divisors (see below), whose sum is σ = 49285180056. Its totient is φ = 7040740000.

The previous prime is 21122219999. The next prime is 21122220043. The reversal of 21122220012 is 21002222112.

It is a tau number, because it is divible by the number of its divisors (12).

It is a super-2 number, since 2×21122220012² (a number of 21 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21122219973 and 21122220000.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 880092489 + ... + 880092512.

It is an arithmetic number, because the mean of its divisors is an integer number (4107098338).

Almost surely, 2^21122220012 is an apocalyptic number.

It is an amenable number.

21122220012 is an abundant number, since it is smaller than the sum of its proper divisors (28162960044).

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

21122220012 is a wasteful number, since it uses less digits than its factorization.

21122220012 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1760185008 (or 1760185006 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 15.

Adding to 21122220012 its reverse (21002222112), we get a palindrome (42124442124).

The spelling of 21122220012 in words is "twenty-one billion, one hundred twenty-two million, two hundred twenty thousand, twelve".