21102111012 has 24 divisors (see below), whose sum is σ = 49263270336. Its totient is φ = 7030463968.

The previous prime is 21102111011. The next prime is 21102111031. The reversal of 21102111012 is 21011120112.

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

It is not an unprimeable number, because it can be changed into a prime (21102111011) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 421968 + ... + 469319.

It is an arithmetic number, because the mean of its divisors is an integer number (2052636264).

Almost surely, 2^21102111012 is an apocalyptic number.

It is an amenable number.

21102111012 is an abundant number, since it is smaller than the sum of its proper divisors (28161159324).

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

21102111012 is a wasteful number, since it uses less digits than its factorization.

21102111012 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 893267 (or 893265 counting only the distinct ones).

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

Adding to 21102111012 its reverse (21011120112), we get a palindrome (42113231124).

The spelling of 21102111012 in words is "twenty-one billion, one hundred two million, one hundred eleven thousand, twelve".