1688400678 has 16 divisors (see below), whose sum is σ = 3485730816. Its totient is φ = 544645320.

The previous prime is 1688400653. The next prime is 1688400697. The reversal of 1688400678 is 8760048861.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4538526 + ... + 4538897.

It is an arithmetic number, because the mean of its divisors is an integer number (217858176).

Almost surely, 2^1688400678 is an apocalyptic number.

1688400678 is an abundant number, since it is smaller than the sum of its proper divisors (1797330138).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1688400678 is a wasteful number, since it uses less digits than its factorization.

1688400678 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9077459.

The product of its (nonzero) digits is 516096, while the sum is 48.

The square root of 1688400678 is about 41090.1530539861. The cubic root of 1688400678 is about 1190.7625642225.

The spelling of 1688400678 in words is "one billion, six hundred eighty-eight million, four hundred thousand, six hundred seventy-eight".