21011013120 has 80 divisors (see below), whose sum is σ = 67169607120. Its totient is φ = 5602934784.

The previous prime is 21011013109. The next prime is 21011013193. The reversal of 21011013120 is 2131011012.

It is a tau number, because it is divible by the number of its divisors (80).

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 = 21011013096 and 21011013105.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1360225 + ... + 1375584.

It is an arithmetic number, because the mean of its divisors is an integer number (839620089).

Almost surely, 2^21011013120 is an apocalyptic number.

21011013120 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21011013120 is an abundant number, since it is smaller than the sum of its proper divisors (46158594000).

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

21011013120 is an equidigital number, since it uses as much as digits as its factorization.

21011013120 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2735835 (or 2735819 counting only the distinct ones).

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

Adding to 21011013120 its reverse (2131011012), we get a palindrome (23142024132).

The spelling of 21011013120 in words is "twenty-one billion, eleven million, thirteen thousand, one hundred twenty".