21002122212 has 24 divisors (see below), whose sum is σ = 49462945056. Its totient is φ = 6935279808.

The previous prime is 21002122171. The next prime is 21002122213. The reversal of 21002122212 is 21222120012.

It is a junction number, because it is equal to n+sod(n) for n = 21002122191 and 21002122200.

It is not an unprimeable number, because it can be changed into a prime (21002122213) 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, 8177113 + ... + 8179680.

It is an arithmetic number, because the mean of its divisors is an integer number (2060956044).

Almost surely, 2^21002122212 is an apocalyptic number.

It is an amenable number.

21002122212 is an abundant number, since it is smaller than the sum of its proper divisors (28460822844).

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

21002122212 is a wasteful number, since it uses less digits than its factorization.

21002122212 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16356907 (or 16356905 counting only the distinct ones).

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

Adding to 21002122212 its reverse (21222120012), we get a palindrome (42224242224).

The spelling of 21002122212 in words is "twenty-one billion, two million, one hundred twenty-two thousand, two hundred twelve".