21002021212 has 12 divisors (see below), whose sum is σ = 38020900680. Its totient is φ = 10138906736.

The previous prime is 21002021197. The next prime is 21002021219. The reversal of 21002021212 is 21212020012.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 21002021192 and 21002021201.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21002021219) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 90525838 + ... + 90526069.

It is an arithmetic number, because the mean of its divisors is an integer number (3168408390).

Almost surely, 2^21002021212 is an apocalyptic number.

It is an amenable number.

21002021212 is a deficient number, since it is larger than the sum of its proper divisors (17018879468).

21002021212 is a wasteful number, since it uses less digits than its factorization.

21002021212 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 181051940 (or 181051938 counting only the distinct ones).

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

Adding to 21002021212 its reverse (21212020012), we get a palindrome (42214041224).

The spelling of 21002021212 in words is "twenty-one billion, two million, twenty-one thousand, two hundred twelve".