1688322749 has 16 divisors (see below), whose sum is σ = 1737590400. Its totient is φ = 1639915200.

The previous prime is 1688322737. The next prime is 1688322781. The reversal of 1688322749 is 9472238861.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1688322749 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 1688322697 and 1688322706.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1688322709) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2408099 + ... + 2408799.

It is an arithmetic number, because the mean of its divisors is an integer number (108599400).

Almost surely, 2^1688322749 is an apocalyptic number.

It is an amenable number.

1688322749 is a deficient number, since it is larger than the sum of its proper divisors (49267651).

1688322749 is a wasteful number, since it uses less digits than its factorization.

1688322749 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1220.

The product of its digits is 1161216, while the sum is 50.

The square root of 1688322749 is about 41089.2047744903. The cubic root of 1688322749 is about 1190.7442438549.

The spelling of 1688322749 in words is "one billion, six hundred eighty-eight million, three hundred twenty-two thousand, seven hundred forty-nine".