21101212012 has 6 divisors (see below), whose sum is σ = 36927121028. Its totient is φ = 10550606004.

The previous prime is 21101211997. The next prime is 21101212031. The reversal of 21101212012 is 21021210112.

It is a super-2 number, since 2×21101212012² (a number of 21 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21101211983 and 21101212001.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2637651498 + ... + 2637651505.

Almost surely, 2^21101212012 is an apocalyptic number.

It is an amenable number.

21101212012 is a deficient number, since it is larger than the sum of its proper divisors (15825909016).

21101212012 is a wasteful number, since it uses less digits than its factorization.

21101212012 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5275303007 (or 5275303005 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 13.

Adding to 21101212012 its reverse (21021210112), we get a palindrome (42122422124).

The spelling of 21101212012 in words is "twenty-one billion, one hundred one million, two hundred twelve thousand, twelve".