1688400677 has 4 divisors (see below), whose sum is σ = 1746621420. Its totient is φ = 1630179936.

The previous prime is 1688400653. The next prime is 1688400697. The reversal of 1688400677 is 7760048861.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 7760048861 = 82163 ⋅94447.

It can be written as a sum of positive squares in 2 ways, for example, as 526886116 + 1161514561 = 22954^2 + 34081^2 .

It is a cyclic number.

It is not a de Polignac number, because 1688400677 - 2¹⁰ = 1688399653 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 (1688400697) 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, 29110328 + ... + 29110385.

It is an arithmetic number, because the mean of its divisors is an integer number (436655355).

Almost surely, 2^1688400677 is an apocalyptic number.

It is an amenable number.

1688400677 is a deficient number, since it is larger than the sum of its proper divisors (58220743).

1688400677 is an equidigital number, since it uses as much as digits as its factorization.

1688400677 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 58220742.

The product of its (nonzero) digits is 451584, while the sum is 47.

The square root of 1688400677 is about 41090.1530418177. The cubic root of 1688400677 is about 1190.7625639874.

The spelling of 1688400677 in words is "one billion, six hundred eighty-eight million, four hundred thousand, six hundred seventy-seven".