211001985 has 12 divisors (see below), whose sum is σ = 365736852. Its totient is φ = 112534368.

The previous prime is 211001981. The next prime is 211002013. The reversal of 211001985 is 589100112.

It can be written as a sum of positive squares in 2 ways, for example, as 108243216 + 102758769 = 10404^2 + 10137^2 .

It is not a de Polignac number, because 211001985 - 2² = 211001981 is a prime.

It is not an unprimeable number, because it can be changed into a prime (211001981) by changing a digit.

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 11 ways as a sum of consecutive naturals, for example, 2344422 + ... + 2344511.

It is an arithmetic number, because the mean of its divisors is an integer number (30478071).

Almost surely, 2^211001985 is an apocalyptic number.

It is an amenable number.

211001985 is a deficient number, since it is larger than the sum of its proper divisors (154734867).

211001985 is a wasteful number, since it uses less digits than its factorization.

211001985 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4688944 (or 4688941 counting only the distinct ones).

The product of its (nonzero) digits is 720, while the sum is 27.

The square root of 211001985 is about 14525.9073726910. The cubic root of 211001985 is about 595.3360481933.

The spelling of 211001985 in words is "two hundred eleven million, one thousand, nine hundred eighty-five".