685632691 has 4 divisors (see below), whose sum is σ = 715442832. Its totient is φ = 655822552.

The previous prime is 685632683. The next prime is 685632697. The reversal of 685632691 is 196236586.

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

It is not a de Polignac number, because 685632691 - 2³ = 685632683 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (685632697) 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, 14905036 + ... + 14905081.

It is an arithmetic number, because the mean of its divisors is an integer number (178860708).

Almost surely, 2^685632691 is an apocalyptic number.

685632691 is a deficient number, since it is larger than the sum of its proper divisors (29810141).

685632691 is a wasteful number, since it uses less digits than its factorization.

685632691 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 29810140.

The product of its digits is 466560, while the sum is 46.

The square root of 685632691 is about 26184.5888071591. The cubic root of 685632691 is about 881.7872985448.

The spelling of 685632691 in words is "six hundred eighty-five million, six hundred thirty-two thousand, six hundred ninety-one".