21101011212 has 12 divisors (see below), whose sum is σ = 49235692856. Its totient is φ = 7033670400.

The previous prime is 21101011193. The next prime is 21101011219. The reversal of 21101011212 is 21211010112.

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

It is a Harshad number since it is a multiple of its sum of digits (12), and also a Moran number because the ratio is a prime number: 1758417601 = 21101011212 / (2 + 1 + 1 + 0 + 1 + 0 + 1 + 1 + 2 + 1 + 2).

It is not an unprimeable number, because it can be changed into a prime (21101011219) 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, 879208789 + ... + 879208812.

Almost surely, 2^21101011212 is an apocalyptic number.

It is an amenable number.

21101011212 is an abundant number, since it is smaller than the sum of its proper divisors (28134681644).

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

21101011212 is a wasteful number, since it uses less digits than its factorization.

21101011212 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1758417608 (or 1758417606 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 12.

Adding to 21101011212 its reverse (21211010112), we get a palindrome (42312021324).

It can be divided in two parts, 211010 and 11212, that added together give a palindrome (222222).

The spelling of 21101011212 in words is "twenty-one billion, one hundred one million, eleven thousand, two hundred twelve".