21012012000 has 576 divisors, whose sum is σ = 85857408000. Its totient is φ = 4767206400.

The previous prime is 21012011989. The next prime is 21012012067. The reversal of 21012012000 is 21021012.

It is a Harshad number since it is a multiple of its sum of digits (9).

It is a super Niven number, because it is divisible the sum of any subset of its (nonzero) digits.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 50147791 + ... + 50148209.

It is an arithmetic number, because the mean of its divisors is an integer number (149058000).

Almost surely, 2^21012012000 is an apocalyptic number.

21012012000 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21012012000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (42928704000).

21012012000 is an abundant number, since it is smaller than the sum of its proper divisors (64845396000).

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

21012012000 is a wasteful number, since it uses less digits than its factorization.

21012012000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 656 (or 635 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 9.

Adding to 21012012000 its reverse (21021012), we get a palindrome (21033033012).

The spelling of 21012012000 in words is "twenty-one billion, twelve million, twelve thousand".