1688340407 has 4 divisors (see below), whose sum is σ = 1818212760. Its totient is φ = 1558468056.

The previous prime is 1688340391. The next prime is 1688340427. The reversal of 1688340407 is 7040438861.

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

It is a cyclic number.

It is not a de Polignac number, because 1688340407 - 2⁴ = 1688340391 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1688340427) 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, 64936157 + ... + 64936182.

It is an arithmetic number, because the mean of its divisors is an integer number (454553190).

Almost surely, 2^1688340407 is an apocalyptic number.

1688340407 is a deficient number, since it is larger than the sum of its proper divisors (129872353).

1688340407 is a wasteful number, since it uses less digits than its factorization.

1688340407 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 129872352.

The product of its (nonzero) digits is 129024, while the sum is 41.

The square root of 1688340407 is about 41089.4196478850. The cubic root of 1688340407 is about 1190.7483951323.

The spelling of 1688340407 in words is "one billion, six hundred eighty-eight million, three hundred forty thousand, four hundred seven".