211999971 has 8 divisors (see below), whose sum is σ = 289561104. Its totient is φ = 137886080.

The previous prime is 211999969. The next prime is 212000003. The reversal of 211999971 is 179999112.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 211999971 - 2¹ = 211999969 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 211999971.

It is not an unprimeable number, because it can be changed into a prime (211999961) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 861666 + ... + 861911.

It is an arithmetic number, because the mean of its divisors is an integer number (36195138).

Almost surely, 2^211999971 is an apocalyptic number.

211999971 is a deficient number, since it is larger than the sum of its proper divisors (77561133).

211999971 is a wasteful number, since it uses less digits than its factorization.

211999971 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1723621.

The product of its digits is 91854, while the sum is 48.

The square root of 211999971 is about 14560.2187826969. The cubic root of 211999971 is about 596.2731685858.

The spelling of 211999971 in words is "two hundred eleven million, nine hundred ninety-nine thousand, nine hundred seventy-one".