1688253840 has 600 divisors, whose sum is σ = 7363513080. Its totient is φ = 355332096.

The previous prime is 1688253823. The next prime is 1688253851. The reversal of 1688253840 is 483528861.

It can be written as a sum of positive squares in 4 ways, for example, as 221057424 + 1467196416 = 14868^2 + 38304^2 .

It is a Harshad number since it is a multiple of its sum of digits (45).

It is an unprimeable number.

It is a polite number, since it can be written in 119 ways as a sum of consecutive naturals, for example, 4127556 + ... + 4127964.

Almost surely, 2^1688253840 is an apocalyptic number.

1688253840 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 1688253840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3681756540).

1688253840 is an abundant number, since it is smaller than the sum of its proper divisors (5675259240).

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

1688253840 is a wasteful number, since it uses less digits than its factorization.

1688253840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 461 (or 439 counting only the distinct ones).

The product of its (nonzero) digits is 368640, while the sum is 45.

The square root of 1688253840 is about 41088.3662366855. The cubic root of 1688253840 is about 1190.7280435339.

The spelling of 1688253840 in words is "one billion, six hundred eighty-eight million, two hundred fifty-three thousand, eight hundred forty".