213687811 has 4 divisors (see below), whose sum is σ = 216392800. Its totient is φ = 210982824.

The previous prime is 213687797. The next prime is 213687823. The reversal of 213687811 is 118786312.

213687811 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 not a de Polignac number, because 213687811 - 2¹¹ = 213685763 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (213685811) 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, 1352376 + ... + 1352533.

It is an arithmetic number, because the mean of its divisors is an integer number (54098200).

Almost surely, 2^213687811 is an apocalyptic number.

213687811 is a deficient number, since it is larger than the sum of its proper divisors (2704989).

213687811 is an equidigital number, since it uses as much as digits as its factorization.

213687811 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2704988.

The product of its digits is 16128, while the sum is 37.

The square root of 213687811 is about 14618.0645435707. The cubic root of 213687811 is about 597.8513993019.

The spelling of 213687811 in words is "two hundred thirteen million, six hundred eighty-seven thousand, eight hundred eleven".