21011112012 has 48 divisors (see below), whose sum is σ = 54012397824. Its totient is φ = 6303960000.

The previous prime is 21011112011. The next prime is 21011112047. The reversal of 21011112012 is 21021111012.

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 (21011112011) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 774664 + ... + 801327.

It is an arithmetic number, because the mean of its divisors is an integer number (1125258288).

Almost surely, 2^21011112012 is an apocalyptic number.

21011112012 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

It is an amenable number.

21011112012 is an abundant number, since it is smaller than the sum of its proper divisors (33001285812).

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

21011112012 is a wasteful number, since it uses less digits than its factorization.

21011112012 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1576110 (or 1576108 counting only the distinct ones).

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

Adding to 21011112012 its reverse (21021111012), we get a palindrome (42032223024).

The spelling of 21011112012 in words is "twenty-one billion, eleven million, one hundred twelve thousand, twelve".