1691383680 has 640 divisors, whose sum is σ = 7108992000. Its totient is φ = 375238656.

The previous prime is 1691383663. The next prime is 1691383691. The reversal of 1691383680 is 863831961.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (640).

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

It is a congruent number.

It is an unprimeable number.

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 79 ways as a sum of consecutive naturals, for example, 21409881 + ... + 21409959.

It is an arithmetic number, because the mean of its divisors is an integer number (11107800).

Almost surely, 2^1691383680 is an apocalyptic number.

1691383680 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 1691383680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3554496000).

1691383680 is an abundant number, since it is smaller than the sum of its proper divisors (5417608320).

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

1691383680 is an equidigital number, since it uses as much as digits as its factorization.

1691383680 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 176 (or 155 counting only the distinct ones).

The product of its (nonzero) digits is 186624, while the sum is 45.

The square root of 1691383680 is about 41126.4352941025. The cubic root of 1691383680 is about 1191.4634162841.

The spelling of 1691383680 in words is "one billion, six hundred ninety-one million, three hundred eighty-three thousand, six hundred eighty".