1691688768 has 448 divisors, whose sum is σ = 6067519488. Its totient is φ = 402554880.

The previous prime is 1691688763. The next prime is 1691688799. The reversal of 1691688768 is 8678861961.

It is a tau number, because it is divible by the number of its divisors (448).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1691688763) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 13320321 + ... + 13320447.

Almost surely, 2^1691688768 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 1691688768, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3033759744).

1691688768 is an abundant number, since it is smaller than the sum of its proper divisors (4375830720).

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

1691688768 is a wasteful number, since it uses less digits than its factorization.

1691688768 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 230 (or 220 counting only the distinct ones).

The product of its digits is 6967296, while the sum is 60.

The square root of 1691688768 is about 41130.1442739993. The cubic root of 1691688768 is about 1191.5350498114.

The spelling of 1691688768 in words is "one billion, six hundred ninety-one million, six hundred eighty-eight thousand, seven hundred sixty-eight".