1689891840 has 792 divisors, whose sum is σ = 7480032768. Its totient is φ = 345047040.

The previous prime is 1689891829. The next prime is 1689891899. The reversal of 1689891840 is 481989861.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 54512625 + ... + 54512655.

Almost surely, 2^1689891840 is an apocalyptic number.

1689891840 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 1689891840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3740016384).

1689891840 is an abundant number, since it is smaller than the sum of its proper divisors (5790140928).

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

1689891840 is a wasteful number, since it uses less digits than its factorization.

1689891840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 95 (or 61 counting only the distinct ones).

The product of its (nonzero) digits is 995328, while the sum is 54.

The square root of 1689891840 is about 41108.2940536335. The cubic root of 1689891840 is about 1191.1130137012.

The spelling of 1689891840 in words is "one billion, six hundred eighty-nine million, eight hundred ninety-one thousand, eight hundred forty".