211997867 has 4 divisors (see below), whose sum is σ = 212053920. Its totient is φ = 211941816.

The previous prime is 211997861. The next prime is 211997881. The reversal of 211997867 is 768799112.

211997867 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-211997867 is a prime.

It is a super-2 number, since 2×211997867² = 89886191225099378, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (211997861) 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, 21908 + ... + 30065.

It is an arithmetic number, because the mean of its divisors is an integer number (53013480).

Almost surely, 2^211997867 is an apocalyptic number.

211997867 is a deficient number, since it is larger than the sum of its proper divisors (56053).

211997867 is an equidigital number, since it uses as much as digits as its factorization.

211997867 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 56052.

The product of its digits is 381024, while the sum is 50.

The square root of 211997867 is about 14560.1465308561. The cubic root of 211997867 is about 596.2711960024.

The spelling of 211997867 in words is "two hundred eleven million, nine hundred ninety-seven thousand, eight hundred sixty-seven".