211671987 has 16 divisors (see below), whose sum is σ = 285602592. Its totient is φ = 139438080.

The previous prime is 211671979. The next prime is 211671991. The reversal of 211671987 is 789176112.

It is not a de Polignac number, because 211671987 - 2³ = 211671979 is a prime.

It is not an unprimeable number, because it can be changed into a prime (211671917) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 97983 + ... + 100119.

It is an arithmetic number, because the mean of its divisors is an integer number (17850162).

Almost surely, 2^211671987 is an apocalyptic number.

211671987 is a deficient number, since it is larger than the sum of its proper divisors (73930605).

211671987 is a wasteful number, since it uses less digits than its factorization.

211671987 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2518.

The product of its digits is 42336, while the sum is 42.

The square root of 211671987 is about 14548.9514055137. The cubic root of 211671987 is about 595.9655128837.

The spelling of 211671987 in words is "two hundred eleven million, six hundred seventy-one thousand, nine hundred eighty-seven".