685469991 has 4 divisors (see below), whose sum is σ = 913959992. Its totient is φ = 456979992.

The previous prime is 685469977. The next prime is 685469999. The reversal of 685469991 is 199964586.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 685469991 - 2⁵ = 685469959 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 (685469999) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 114244996 + ... + 114245001.

It is an arithmetic number, because the mean of its divisors is an integer number (228489998).

Almost surely, 2^685469991 is an apocalyptic number.

685469991 is a deficient number, since it is larger than the sum of its proper divisors (228490001).

685469991 is a wasteful number, since it uses less digits than its factorization.

685469991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 228490000.

The product of its digits is 4199040, while the sum is 57.

The square root of 685469991 is about 26181.4818335403. The cubic root of 685469991 is about 881.7175439250.

The spelling of 685469991 in words is "six hundred eighty-five million, four hundred sixty-nine thousand, nine hundred ninety-one".