21002001120 has 144 divisors (see below), whose sum is σ = 75441497040. Its totient is φ = 5305761792.

The previous prime is 21002001107. The next prime is 21002001157. The reversal of 21002001120 is 2110020012.

It is a tau number, because it is divible by the number of its divisors (144).

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 356449 + ... + 411168.

It is an arithmetic number, because the mean of its divisors is an integer number (523899285).

Almost surely, 2^21002001120 is an apocalyptic number.

21002001120 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21002001120 is an abundant number, since it is smaller than the sum of its proper divisors (54439495920).

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

21002001120 is a wasteful number, since it uses less digits than its factorization.

21002001120 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 767657 (or 767646 counting only the distinct ones).

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

Adding to 21002001120 its reverse (2110020012), we get a palindrome (23112021132).

The spelling of 21002001120 in words is "twenty-one billion, two million, one thousand, one hundred twenty".