1638968760 has 576 divisors, whose sum is σ = 6577459200. Its totient is φ = 350438400.

The previous prime is 1638968699. The next prime is 1638968797. The reversal of 1638968760 is 678698361.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 1638968697 and 1638968706.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 143 ways as a sum of consecutive naturals, for example, 20746401 + ... + 20746479.

It is an arithmetic number, because the mean of its divisors is an integer number (11419200).

Almost surely, 2^1638968760 is an apocalyptic number.

1638968760 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 1638968760, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3288729600).

1638968760 is an abundant number, since it is smaller than the sum of its proper divisors (4938490440).

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

1638968760 is a wasteful number, since it uses less digits than its factorization.

1638968760 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 164 (or 144 counting only the distinct ones).

The product of its (nonzero) digits is 2612736, while the sum is 54.

The square root of 1638968760 is about 40484.1791321005. The cubic root of 1638968760 is about 1179.0264784804.

The spelling of 1638968760 in words is "one billion, six hundred thirty-eight million, nine hundred sixty-eight thousand, seven hundred sixty".