213838639 has 4 divisors (see below), whose sum is σ = 244387024. Its totient is φ = 183290256.

The previous prime is 213838633. The next prime is 213838643. The reversal of 213838639 is 936838312.

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 213838639 - 2¹⁷ = 213707567 is a prime.

It is a super-3 number, since 3×213838639³ (a number of 26 digits) contains 333 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 213838595 and 213838604.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (213838633) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 15274182 + ... + 15274195.

It is an arithmetic number, because the mean of its divisors is an integer number (61096756).

Almost surely, 2^213838639 is an apocalyptic number.

213838639 is a deficient number, since it is larger than the sum of its proper divisors (30548385).

213838639 is an equidigital number, since it uses as much as digits as its factorization.

213838639 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 30548384.

The product of its digits is 186624, while the sum is 43.

The square root of 213838639 is about 14623.2225928487. Note that the first 3 decimals coincide. The cubic root of 213838639 is about 597.9920273878.

The spelling of 213838639 in words is "two hundred thirteen million, eight hundred thirty-eight thousand, six hundred thirty-nine".