1639319680 has 128 divisors (see below), whose sum is σ = 4124390400. Its totient is φ = 622202880.

The previous prime is 1639319663. The next prime is 1639319699. The reversal of 1639319680 is 869139361.

It is a tau number, because it is divible by the number of its divisors (128).

It is a self number, because there is not a number n which added to its sum of digits gives 1639319680.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1050741 + ... + 1052299.

It is an arithmetic number, because the mean of its divisors is an integer number (32221800).

Almost surely, 2^1639319680 is an apocalyptic number.

1639319680 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 1639319680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2062195200).

1639319680 is an abundant number, since it is smaller than the sum of its proper divisors (2485070720).

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

1639319680 is a wasteful number, since it uses less digits than its factorization.

1639319680 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1662 (or 1650 counting only the distinct ones).

The product of its (nonzero) digits is 209952, while the sum is 46.

The square root of 1639319680 is about 40488.5129388571. The cubic root of 1639319680 is about 1179.1106196909.

The spelling of 1639319680 in words is "one billion, six hundred thirty-nine million, three hundred nineteen thousand, six hundred eighty".