21111001002000 has 800 divisors, whose sum is σ = 93851757103104. Its totient is φ = 4454186112000.

The previous prime is 21111001001989. The next prime is 21111001002023. The reversal of 21111001002000 is 20010011112.

It is a happy number.

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 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 159 ways as a sum of consecutive naturals, for example, 14025985 + ... + 15458015.

Almost surely, 2^{21111001002000} is an apocalyptic number.

21111001002000 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 21111001002000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (46925878551552).

21111001002000 is an abundant number, since it is smaller than the sum of its proper divisors (72740756101104).

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

21111001002000 is a wasteful number, since it uses less digits than its factorization.

21111001002000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1432086 (or 1432061 counting only the distinct ones).

The product of its (nonzero) digits is 4, while the sum is 9.

Adding to 21111001002000 its reverse (20010011112), we get a palindrome (21131011013112).

The spelling of 21111001002000 in words is "twenty-one trillion, one hundred eleven billion, one million, two thousand".