211242987887 has 4 divisors (see below), whose sum is σ = 223669046016. Its totient is φ = 198816929760.

The previous prime is 211242987883. The next prime is 211242987889. The reversal of 211242987887 is 788789242112.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 211242987887 - 2² = 211242987883 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (211242987881) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6213029039 + ... + 6213029072.

It is an arithmetic number, because the mean of its divisors is an integer number (55917261504).

Almost surely, 2^211242987887 is an apocalyptic number.

211242987887 is a deficient number, since it is larger than the sum of its proper divisors (12426058129).

211242987887 is a wasteful number, since it uses less digits than its factorization.

211242987887 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12426058128.

The product of its digits is 7225344, while the sum is 59.

The spelling of 211242987887 in words is "two hundred eleven billion, two hundred forty-two million, nine hundred eighty-seven thousand, eight hundred eighty-seven".