211665520640 has 384 divisors, whose sum is σ = 619635744000. Its totient is φ = 67777855488.

The previous prime is 211665520637. The next prime is 211665520669. The reversal of 211665520640 is 46025566112.

It is a Harshad number since it is a multiple of its sum of digits (38).

It is a junction number, because it is equal to n+sod(n) for n = 211665520594 and 211665520603.

It is an unprimeable number.

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 31 ways as a sum of consecutive naturals, for example, 99419096 + ... + 99421224.

It is an arithmetic number, because the mean of its divisors is an integer number (1613634750).

Almost surely, 2^211665520640 is an apocalyptic number.

211665520640 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 211665520640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (309817872000).

211665520640 is an abundant number, since it is smaller than the sum of its proper divisors (407970223360).

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

211665520640 is a wasteful number, since it uses less digits than its factorization.

211665520640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2255 (or 2235 counting only the distinct ones).

The product of its (nonzero) digits is 86400, while the sum is 38.

The spelling of 211665520640 in words is "two hundred eleven billion, six hundred sixty-five million, five hundred twenty thousand, six hundred forty".