687631673 has 4 divisors (see below), whose sum is σ = 711343140. Its totient is φ = 663920208.

The previous prime is 687631649. The next prime is 687631723. The reversal of 687631673 is 376136786.

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

It can be written as a sum of positive squares in 2 ways, for example, as 442176784 + 245454889 = 21028^2 + 15667^2 .

It is a cyclic number.

It is not a de Polignac number, because 687631673 - 2¹⁶ = 687566137 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (687631613) 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, 11855690 + ... + 11855747.

It is an arithmetic number, because the mean of its divisors is an integer number (177835785).

Almost surely, 2^687631673 is an apocalyptic number.

It is an amenable number.

687631673 is a deficient number, since it is larger than the sum of its proper divisors (23711467).

687631673 is a wasteful number, since it uses less digits than its factorization.

687631673 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23711466.

The product of its digits is 762048, while the sum is 47.

The square root of 687631673 is about 26222.7319896307. The cubic root of 687631673 is about 882.6434258779.

The spelling of 687631673 in words is "six hundred eighty-seven million, six hundred thirty-one thousand, six hundred seventy-three".