1691682408 has 224 divisors, whose sum is σ = 5230529640. Its totient is φ = 509483520.

The previous prime is 1691682401. The next prime is 1691682409. The reversal of 1691682408 is 8042861961.

1691682408 is a `hidden beast` number, since 169 + 1 + 6 + 82 + 408 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 767400804 + 924281604 = 27702^2 + 30402^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1691682401) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 55 ways as a sum of consecutive naturals, for example, 4018038 + ... + 4018458.

Almost surely, 2^1691682408 is an apocalyptic number.

1691682408 is a gapful number since it is divisible by the number (18) 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 1691682408, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2615264820).

1691682408 is an abundant number, since it is smaller than the sum of its proper divisors (3538847232).

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

1691682408 is a wasteful number, since it uses less digits than its factorization.

1691682408 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 511 (or 492 counting only the distinct ones).

The product of its (nonzero) digits is 165888, while the sum is 45.

The square root of 1691682408 is about 41130.0669583700. The cubic root of 1691682408 is about 1191.5335565949.

The spelling of 1691682408 in words is "one billion, six hundred ninety-one million, six hundred eighty-two thousand, four hundred eight".