21002101212 has 48 divisors (see below), whose sum is σ = 52205650560. Its totient is φ = 6552330048.

The previous prime is 21002101181. The next prime is 21002101249. The reversal of 21002101212 is 21210120012.

It is a Harshad number since it is a multiple of its sum of digits (12).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 535983 + ... + 573830.

It is an arithmetic number, because the mean of its divisors is an integer number (1087617720).

Almost surely, 2^21002101212 is an apocalyptic number.

It is an amenable number.

21002101212 is an abundant number, since it is smaller than the sum of its proper divisors (31203549348).

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

21002101212 is a wasteful number, since it uses less digits than its factorization.

21002101212 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1109922 (or 1109920 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 12.

Adding to 21002101212 its reverse (21210120012), we get a palindrome (42212221224).

The spelling of 21002101212 in words is "twenty-one billion, two million, one hundred one thousand, two hundred twelve".