21110011020 has 240 divisors, whose sum is σ = 75805063488. Its totient is φ = 4817387520.

The previous prime is 21110010983. The next prime is 21110011049. The reversal of 21110011020 is 2011001112.

It is a happy number.

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

It is a junction number, because it is equal to n+sod(n) for n = 21110010993 and 21110011011.

It is an unprimeable number.

It is a polite number, since it can be written in 79 ways as a sum of consecutive naturals, for example, 9989484 + ... + 9991596.

Almost surely, 2^21110011020 is an apocalyptic number.

21110011020 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 21110011020, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (37902531744).

21110011020 is an abundant number, since it is smaller than the sum of its proper divisors (54695052468).

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

21110011020 is a wasteful number, since it uses less digits than its factorization.

21110011020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3022 (or 3011 counting only the distinct ones).

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

Adding to 21110011020 its reverse (2011001112), we get a palindrome (23121012132).

The spelling of 21110011020 in words is "twenty-one billion, one hundred ten million, eleven thousand, twenty".