1691721088 has 96 divisors (see below), whose sum is σ = 3674790720. Its totient is φ = 774835200.

The previous prime is 1691721071. The next prime is 1691721121. The reversal of 1691721088 is 8801271961.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1431858 + ... + 1433038.

It is an arithmetic number, because the mean of its divisors is an integer number (38279070).

Almost surely, 2^1691721088 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1691721088, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1837395360).

1691721088 is an abundant number, since it is smaller than the sum of its proper divisors (1983069632).

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

1691721088 is a wasteful number, since it uses less digits than its factorization.

1691721088 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1264 (or 1233 counting only the distinct ones).

The product of its (nonzero) digits is 48384, while the sum is 43.

The square root of 1691721088 is about 41130.5371713038. The cubic root of 1691721088 is about 1191.5426379226.

The spelling of 1691721088 in words is "one billion, six hundred ninety-one million, seven hundred twenty-one thousand, eighty-eight".