211021000020 has 72 divisors (see below), whose sum is σ = 640888695720. Its totient is φ = 56202670080.

The previous prime is 211020999991. The next prime is 211021000079. The reversal of 211021000020 is 20000120112.

It can be written as a sum of positive squares in 4 ways, for example, as 50673611664 + 160347388356 = 225108^2 + 400434^2 .

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 = 211020999966 and 211021000011.

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, 578941 + ... + 870180.

It is an arithmetic number, because the mean of its divisors is an integer number (8901231885).

Almost surely, 2^211021000020 is an apocalyptic number.

211021000020 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

211021000020 is an abundant number, since it is smaller than the sum of its proper divisors (429867695700).

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

211021000020 is a wasteful number, since it uses less digits than its factorization.

211021000020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1449945 (or 1449940 counting only the distinct ones).

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

Adding to 211021000020 its reverse (20000120112), we get a palindrome (231021120132).

The spelling of 211021000020 in words is "two hundred eleven billion, twenty-one million, twenty", and thus it is an aban number.