211223009920 has 64 divisors (see below), whose sum is σ = 543797722440. Its totient is φ = 77990031360.

The previous prime is 211223009887. The next prime is 211223009927. The reversal of 211223009920 is 29900322112.

211223009920 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 4 ways, for example, as 191696860224 + 19526149696 = 437832^2 + 139736^2 .

It is a tau number, because it is divible by the number of its divisors (64).

It is not an unprimeable number, because it can be changed into a prime (211223009927) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 12685371 + ... + 12702010.

Almost surely, 2^211223009920 is an apocalyptic number.

211223009920 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

211223009920 is an abundant number, since it is smaller than the sum of its proper divisors (332574712520).

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

211223009920 is a wasteful number, since it uses less digits than its factorization.

211223009920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25387413 (or 25387401 counting only the distinct ones).

The product of its (nonzero) digits is 3888, while the sum is 31.

The spelling of 211223009920 in words is "two hundred eleven billion, two hundred twenty-three million, nine thousand, nine hundred twenty".