211959990 has 80 divisors (see below), whose sum is σ = 621775440. Its totient is φ = 51382080.

The previous prime is 211959959. The next prime is 211960003. The reversal of 211959990 is 99959112.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 2985 + ... + 20804.

It is an arithmetic number, because the mean of its divisors is an integer number (7772193).

Almost surely, 2^211959990 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 211959990, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (310887720).

211959990 is an abundant number, since it is smaller than the sum of its proper divisors (409815450).

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

211959990 is a wasteful number, since it uses less digits than its factorization.

211959990 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23819 (or 23810 counting only the distinct ones).

The product of its (nonzero) digits is 65610, while the sum is 45.

The square root of 211959990 is about 14558.8457646889. The cubic root of 211959990 is about 596.2356825801.

The spelling of 211959990 in words is "two hundred eleven million, nine hundred fifty-nine thousand, nine hundred ninety".