211555706640 has 160 divisors (see below), whose sum is σ = 665440551936. Its totient is φ = 55588431360.

The previous prime is 211555706617. The next prime is 211555706651. The reversal of 211555706640 is 46607555112.

It is a junction number, because it is equal to n+sod(n) for n = 211555706592 and 211555706601.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 52532307 + ... + 52536333.

Almost surely, 2^211555706640 is an apocalyptic number.

211555706640 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 211555706640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (332720275968).

211555706640 is an abundant number, since it is smaller than the sum of its proper divisors (453884845296).

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

211555706640 is a wasteful number, since it uses less digits than its factorization.

211555706640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7197 (or 7191 counting only the distinct ones).

The product of its (nonzero) digits is 252000, while the sum is 42.

The spelling of 211555706640 in words is "two hundred eleven billion, five hundred fifty-five million, seven hundred six thousand, six hundred forty".