21001001211120 has 320 divisors, whose sum is σ = 75188968740864. Its totient is φ = 4749700300800.

The previous prime is 21001001211079. The next prime is 21001001211131. The reversal of 21001001211120 is 2111210010012.

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

It is a junction number, because it is equal to n+sod(n) for n = 21001001211096 and 21001001211105.

It is a congruent number.

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 63 ways as a sum of consecutive naturals, for example, 112481845 + ... + 112668395.

Almost surely, 2^{21001001211120} is an apocalyptic number.

21001001211120 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 21001001211120, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (37594484370432).

21001001211120 is an abundant number, since it is smaller than the sum of its proper divisors (54187967529744).

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

21001001211120 is a wasteful number, since it uses less digits than its factorization.

21001001211120 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 187280 (or 187274 counting only the distinct ones).

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

Adding to 21001001211120 its reverse (2111210010012), we get a palindrome (23112211221132).

The spelling of 21001001211120 in words is "twenty-one trillion, one billion, one million, two hundred eleven thousand, one hundred twenty".