211976991 has 12 divisors (see below), whose sum is σ = 307901880. Its totient is φ = 140527440.

The previous prime is 211976983. The next prime is 211977001. The reversal of 211976991 is 199679112.

It is not a de Polignac number, because 211976991 - 2³ = 211976983 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (211976291) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 64180 + ... + 67401.

It is an arithmetic number, because the mean of its divisors is an integer number (25658490).

Almost surely, 2^211976991 is an apocalyptic number.

211976991 is a deficient number, since it is larger than the sum of its proper divisors (95924889).

211976991 is a wasteful number, since it uses less digits than its factorization.

211976991 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 131766 (or 131763 counting only the distinct ones).

The product of its digits is 61236, while the sum is 45.

The square root of 211976991 is about 14559.4296248170. The cubic root of 211976991 is about 596.2516232172.

The spelling of 211976991 in words is "two hundred eleven million, nine hundred seventy-six thousand, nine hundred ninety-one".