1688930391 has 8 divisors (see below), whose sum is σ = 2329559280. Its totient is φ = 1087127552.

The previous prime is 1688930381. The next prime is 1688930413. The reversal of 1688930391 is 1930398861.

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 1688930391 - 2¹¹ = 1688928343 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1688930391.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1688930351) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 9706410 + ... + 9706583.

It is an arithmetic number, because the mean of its divisors is an integer number (291194910).

Almost surely, 2^1688930391 is an apocalyptic number.

1688930391 is a deficient number, since it is larger than the sum of its proper divisors (640628889).

1688930391 is a wasteful number, since it uses less digits than its factorization.

1688930391 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19413025.

The product of its (nonzero) digits is 279936, while the sum is 48.

The square root of 1688930391 is about 41096.5982898828. The cubic root of 1688930391 is about 1190.8870797805.

The spelling of 1688930391 in words is "one billion, six hundred eighty-eight million, nine hundred thirty thousand, three hundred ninety-one".