1688307931 has 8 divisors (see below), whose sum is σ = 1693954080. Its totient is φ = 1682671872.

The previous prime is 1688307923. The next prime is 1688307941. The reversal of 1688307931 is 1397038861.

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 1688307931 - 2³ = 1688307923 is a prime.

It is a super-2 number, since 2×1688307931² = 5700767339755001522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1688307911) 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, 465481 + ... + 469093.

It is an arithmetic number, because the mean of its divisors is an integer number (211744260).

Almost surely, 2^1688307931 is an apocalyptic number.

1688307931 is a deficient number, since it is larger than the sum of its proper divisors (5646149).

1688307931 is an equidigital number, since it uses as much as digits as its factorization.

1688307931 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5045.

The product of its (nonzero) digits is 217728, while the sum is 46.

The square root of 1688307931 is about 41089.0244590937. The cubic root of 1688307931 is about 1190.7407602200.

The spelling of 1688307931 in words is "one billion, six hundred eighty-eight million, three hundred seven thousand, nine hundred thirty-one".