21110000020 has 24 divisors (see below), whose sum is σ = 44470858824. Its totient is φ = 8417360256.

The previous prime is 21110000003. The next prime is 21110000057. The reversal of 21110000020 is 2000001112.

It can be written as a sum of positive squares in 4 ways, for example, as 155700484 + 20954299536 = 12478^2 + 144756^2 .

It is a junction number, because it is equal to n+sod(n) for n = 21109999958 and 21110000012.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1658487 + ... + 1671166.

It is an arithmetic number, because the mean of its divisors is an integer number (1852952451).

Almost surely, 2^21110000020 is an apocalyptic number.

21110000020 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21110000020 is an abundant number, since it is smaller than the sum of its proper divisors (23360858804).

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

21110000020 is a wasteful number, since it uses less digits than its factorization.

21110000020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3329979 (or 3329977 counting only the distinct ones).

The product of its (nonzero) digits is 4, while the sum is 7.

Adding to 21110000020 its reverse (2000001112), we get a palindrome (23110001132).

The spelling of 21110000020 in words is "twenty-one billion, one hundred ten million, twenty", and thus it is an aban number.