21012021012 has 96 divisors (see below), whose sum is σ = 52940369664. Its totient is φ = 6462720000.

The previous prime is 21012021001. The next prime is 21012021049.

21012021012 is nontrivially palindromic in base 10.

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

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 2117262 + ... + 2127162.

It is an arithmetic number, because the mean of its divisors is an integer number (551462184).

Almost surely, 2^21012021012 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 21012021012, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26470184832).

21012021012 is an abundant number, since it is smaller than the sum of its proper divisors (31928348652).

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

21012021012 is a wasteful number, since it uses less digits than its factorization.

21012021012 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10129 (or 10127 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 12.

It can be divided in two parts, 210120 and 21012, that added together give a palindrome (231132).

The spelling of 21012021012 in words is "twenty-one billion, twelve million, twenty-one thousand, twelve".