211972171893 has 12 divisors (see below), whose sum is σ = 289691105184. Its totient is φ = 137868076000.

The previous prime is 211972171883. The next prime is 211972171909. The reversal of 211972171893 is 398171279112.

It is not a de Polignac number, because 211972171893 - 2⁹ = 211972171381 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (211972171883) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 21011433 + ... + 21021518.

It is an arithmetic number, because the mean of its divisors is an integer number (24140925432).

Almost surely, 2^211972171893 is an apocalyptic number.

It is an amenable number.

211972171893 is a deficient number, since it is larger than the sum of its proper divisors (77718933291).

211972171893 is an equidigital number, since it uses as much as digits as its factorization.

211972171893 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 42033036 (or 42032995 counting only the distinct ones).

The product of its digits is 381024, while the sum is 51.

The spelling of 211972171893 in words is "two hundred eleven billion, nine hundred seventy-two million, one hundred seventy-one thousand, eight hundred ninety-three".