213663811 has 4 divisors (see below), whose sum is σ = 220556224. Its totient is φ = 206771400.

The previous prime is 213663799. The next prime is 213663817. The reversal of 213663811 is 118366312.

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 213663811 - 2¹⁵ = 213631043 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (31), and also a Moran number because the ratio is a prime number: 6892381 = 213663811 / (2 + 1 + 3 + 6 + 6 + 3 + 8 + 1 + 1).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (213663817) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3446160 + ... + 3446221.

It is an arithmetic number, because the mean of its divisors is an integer number (55139056).

Almost surely, 2^213663811 is an apocalyptic number.

213663811 is a deficient number, since it is larger than the sum of its proper divisors (6892413).

213663811 is an equidigital number, since it uses as much as digits as its factorization.

213663811 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6892412.

The product of its digits is 5184, while the sum is 31.

The square root of 213663811 is about 14617.2436184118. The cubic root of 213663811 is about 597.8290162271.

The spelling of 213663811 in words is "two hundred thirteen million, six hundred sixty-three thousand, eight hundred eleven".