211665420000 has 480 divisors, whose sum is σ = 773919891360. Its totient is φ = 56263680000.

The previous prime is 211665419971. The next prime is 211665420013. The reversal of 211665420000 is 24566112.

211665420000 is a `hidden beast` number, since 2 + 1 + 1 + 6 + 654 + 2 + 0 + 0 + 0 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (480).

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 79 ways as a sum of consecutive naturals, for example, 320219670 + ... + 320220330.

It is an arithmetic number, because the mean of its divisors is an integer number (1612333107).

Almost surely, 2^211665420000 is an apocalyptic number.

211665420000 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 211665420000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (386959945680).

211665420000 is an abundant number, since it is smaller than the sum of its proper divisors (562254471360).

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

211665420000 is an equidigital number, since it uses as much as digits as its factorization.

211665420000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1293 (or 1264 counting only the distinct ones).

The product of its (nonzero) digits is 2880, while the sum is 27.

Adding to 211665420000 its reverse (24566112), we get a palindrome (211689986112).

The spelling of 211665420000 in words is "two hundred eleven billion, six hundred sixty-five million, four hundred twenty thousand".