1688696640 has 224 divisors, whose sum is σ = 5989441920. Its totient is φ = 447897600.

The previous prime is 1688696629. The next prime is 1688696641. The reversal of 1688696640 is 466968861.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1688696641) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 2081835 + ... + 2082645.

It is an arithmetic number, because the mean of its divisors is an integer number (26738580).

Almost surely, 2^1688696640 is an apocalyptic number.

1688696640 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1688696640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2994720960).

1688696640 is an abundant number, since it is smaller than the sum of its proper divisors (4300745280).

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

1688696640 is a wasteful number, since it uses less digits than its factorization.

1688696640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1078 (or 1062 counting only the distinct ones).

The product of its (nonzero) digits is 2985984, while the sum is 54.

The square root of 1688696640 is about 41093.7542699618. The cubic root of 1688696640 is about 1190.8321369420.

It can be divided in two parts, 16886 and 96640, that added together give a triangular number (113526 = T₄₇₆).

The spelling of 1688696640 in words is "one billion, six hundred eighty-eight million, six hundred ninety-six thousand, six hundred forty".