212991660 has 288 divisors, whose sum is σ = 796024320. Its totient is φ = 46303488.

The previous prime is 212991643. The next prime is 212991673. The reversal of 212991660 is 66199212.

212991660 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (36).

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 95 ways as a sum of consecutive naturals, for example, 3178947 + ... + 3179013.

Almost surely, 2^212991660 is an apocalyptic number.

212991660 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 212991660, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (398012160).

212991660 is an abundant number, since it is smaller than the sum of its proper divisors (583032660).

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

212991660 is a wasteful number, since it uses less digits than its factorization.

212991660 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 150 (or 113 counting only the distinct ones).

The product of its (nonzero) digits is 11664, while the sum is 36.

The square root of 212991660 is about 14594.2337928375. The cubic root of 212991660 is about 597.2014673187.

The spelling of 212991660 in words is "two hundred twelve million, nine hundred ninety-one thousand, six hundred sixty".