1690720687 has 8 divisors (see below), whose sum is σ = 1745874432. Its totient is φ = 1635605400.

The previous prime is 1690720673. The next prime is 1690720747. The reversal of 1690720687 is 7860270961.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 1690720687 - 2¹⁵ = 1690687919 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 (1690720627) 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, 99612 + ... + 115342.

It is an arithmetic number, because the mean of its divisors is an integer number (218234304).

Almost surely, 2^1690720687 is an apocalyptic number.

1690720687 is a deficient number, since it is larger than the sum of its proper divisors (55153745).

1690720687 is a wasteful number, since it uses less digits than its factorization.

1690720687 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19229.

The product of its (nonzero) digits is 254016, while the sum is 46.

The square root of 1690720687 is about 41118.3740802090. The cubic root of 1690720687 is about 1191.3077182896.

The spelling of 1690720687 in words is "one billion, six hundred ninety million, seven hundred twenty thousand, six hundred eighty-seven".