685439381 has 8 divisors (see below), whose sum is σ = 751512000. Its totient is φ = 619993440.

The previous prime is 685439329. The next prime is 685439387. The reversal of 685439381 is 183934586.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a de Polignac number, because none of the positive numbers 2^k-685439381 is a prime.

It is a super-2 number, since 2×685439381² = 939654290051326322, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (685439387) 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 7 ways as a sum of consecutive naturals, for example, 154376 + ... + 158753.

It is an arithmetic number, because the mean of its divisors is an integer number (93939000).

Almost surely, 2^685439381 is an apocalyptic number.

It is an amenable number.

685439381 is a deficient number, since it is larger than the sum of its proper divisors (66072619).

685439381 is a wasteful number, since it uses less digits than its factorization.

685439381 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 313339.

The product of its digits is 622080, while the sum is 47.

The square root of 685439381 is about 26180.8972535320. The cubic root of 685439381 is about 881.7044192192.

The spelling of 685439381 in words is "six hundred eighty-five million, four hundred thirty-nine thousand, three hundred eighty-one".