213685439 has 4 divisors (see below), whose sum is σ = 233111400. Its totient is φ = 194259480.

The previous prime is 213685411. The next prime is 213685469. The reversal of 213685439 is 934586312.

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-213685439 is a prime.

It is a super-2 number, since 2×213685439² = 91322933681245442, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 213685396 and 213685405.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (213685469) 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, 9712964 + ... + 9712985.

It is an arithmetic number, because the mean of its divisors is an integer number (58277850).

Almost surely, 2^213685439 is an apocalyptic number.

213685439 is a deficient number, since it is larger than the sum of its proper divisors (19425961).

213685439 is a wasteful number, since it uses less digits than its factorization.

213685439 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19425960.

The product of its digits is 155520, while the sum is 41.

The square root of 213685439 is about 14617.9834108539. The cubic root of 213685439 is about 597.8491871826.

The spelling of 213685439 in words is "two hundred thirteen million, six hundred eighty-five thousand, four hundred thirty-nine".