213820387 has 4 divisors (see below), whose sum is σ = 233258616. Its totient is φ = 194382160.

The previous prime is 213820363. The next prime is 213820403. The reversal of 213820387 is 783028312.

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 213820387 - 2¹⁵ = 213787619 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (213820337) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 9719098 + ... + 9719119.

It is an arithmetic number, because the mean of its divisors is an integer number (58314654).

Almost surely, 2^213820387 is an apocalyptic number.

213820387 is a deficient number, since it is larger than the sum of its proper divisors (19438229).

213820387 is a wasteful number, since it uses less digits than its factorization.

213820387 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19438228.

The product of its (nonzero) digits is 16128, while the sum is 34.

The square root of 213820387 is about 14622.5985036860. The cubic root of 213820387 is about 597.9750132176.

Adding to 213820387 its reverse (783028312), we get a palindrome (996848699).

The spelling of 213820387 in words is "two hundred thirteen million, eight hundred twenty thousand, three hundred eighty-seven".