21311123021000 has 128 divisors (see below), whose sum is σ = 51103725154560. Its totient is φ = 8315689536000.

The previous prime is 21311123020987. The next prime is 21311123021051. The reversal of 21311123021000 is 12032111312.

It is a self number, because there is not a number n which added to its sum of digits gives 21311123021000.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 5356940 + ... + 8445060.

It is an arithmetic number, because the mean of its divisors is an integer number (399247852770).

Almost surely, 2^{21311123021000} is an apocalyptic number.

21311123021000 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 21311123021000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25551862577280).

21311123021000 is an abundant number, since it is smaller than the sum of its proper divisors (29792602133560).

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

21311123021000 is a wasteful number, since it uses less digits than its factorization.

21311123021000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3088312 (or 3088298 counting only the distinct ones).

The product of its (nonzero) digits is 72, while the sum is 17.

Adding to 21311123021000 its reverse (12032111312), we get a palindrome (21323155132312).

The spelling of 21311123021000 in words is "twenty-one trillion, three hundred eleven billion, one hundred twenty-three million, twenty-one thousand".