21011010111012 has 96 divisors (see below), whose sum is σ = 52694481087360. Its totient is φ = 6492054159360.

The previous prime is 21011010111011. The next prime is 21011010111023. The reversal of 21011010111012 is 21011101011012.

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 (21011010111011) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 72035164 + ... + 72326252.

It is an arithmetic number, because the mean of its divisors is an integer number (548900844660).

Almost surely, 2^{21011010111012} is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21011010111012, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26347240543680).

21011010111012 is an abundant number, since it is smaller than the sum of its proper divisors (31683470976348).

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

21011010111012 is a wasteful number, since it uses less digits than its factorization.

21011010111012 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 296461 (or 296459 counting only the distinct ones).

The product of its (nonzero) digits is 4, while the sum is 12.

Adding to 21011010111012 its reverse (21011101011012), we get a palindrome (42022111122024).

The spelling of 21011010111012 in words is "twenty-one trillion, eleven billion, ten million, one hundred eleven thousand, twelve".