685473989 has 4 divisors (see below), whose sum is σ = 685535040. Its totient is φ = 685412940.

The previous prime is 685473959. The next prime is 685474003. The reversal of 685473989 is 989374586.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 685473989 - 2¹² = 685469893 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (685473959) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8279 + ... + 37940.

It is an arithmetic number, because the mean of its divisors is an integer number (171383760).

Almost surely, 2^685473989 is an apocalyptic number.

It is an amenable number.

685473989 is a deficient number, since it is larger than the sum of its proper divisors (61051).

685473989 is a wasteful number, since it uses less digits than its factorization.

685473989 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 61050.

The product of its digits is 13063680, while the sum is 59.

The square root of 685473989 is about 26181.5581851043. The cubic root of 685473989 is about 881.7192581259.

The spelling of 685473989 in words is "six hundred eighty-five million, four hundred seventy-three thousand, nine hundred eighty-nine".