21211111111212 has 72 divisors (see below), whose sum is σ = 60072090313872. Its totient is φ = 6253890249600.

The previous prime is 21211111111199. The next prime is 21211111111217.

21211111111212 is a `hidden beast` number, since 21 + 211 + 111 + 111 + 212 = 666.

21211111111212 is nontrivially palindromic in base 10.

It is a super-2 number, since 2×21211111111212² (a number of 27 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a nude number because it is divisible by every one of its digits.

It is not an unprimeable number, because it can be changed into a prime (21211111111217) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 723815239 + ... + 723844542.

Almost surely, 2^{21211111111212} is an apocalyptic number.

21211111111212 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

It is an amenable number.

21211111111212 is an abundant number, since it is smaller than the sum of its proper divisors (38860979202660).

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

21211111111212 is a wasteful number, since it uses less digits than its factorization.

21211111111212 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1447659839 (or 1447659834 counting only the distinct ones).

The product of its digits is 16, while the sum is 18.

It can be divided in two parts, 2121111 and 1111212, that added together give a palindrome (3232323).

The spelling of 21211111111212 in words is "twenty-one trillion, two hundred eleven billion, one hundred eleven million, one hundred eleven thousand, two hundred twelve".