211638421128 has 16 divisors (see below), whose sum is σ = 529096052880. Its totient is φ = 70546140368.

The previous prime is 211638421123. The next prime is 211638421153. The reversal of 211638421128 is 821124836112.

It is a nude number because it is divisible by every one of its digits.

It is not an unprimeable number, because it can be changed into a prime (211638421123) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 4409133750 + ... + 4409133797.

It is an arithmetic number, because the mean of its divisors is an integer number (33068503305).

Almost surely, 2^211638421128 is an apocalyptic number.

It is an amenable number.

211638421128 is an abundant number, since it is smaller than the sum of its proper divisors (317457631752).

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

211638421128 is a wasteful number, since it uses less digits than its factorization.

211638421128 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8818267556 (or 8818267552 counting only the distinct ones).

The product of its digits is 36864, while the sum is 39.

The spelling of 211638421128 in words is "two hundred eleven billion, six hundred thirty-eight million, four hundred twenty-one thousand, one hundred twenty-eight".