1663375860 has 72 divisors (see below), whose sum is σ = 5055542856. Its totient is φ = 442690560.

The previous prime is 1663375817. The next prime is 1663375867. The reversal of 1663375860 is 685733661.

1663375860 is a `hidden beast` number, since 1 + 6 + 63 + 3 + 7 + 586 + 0 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 280428516 + 1382947344 = 16746^2 + 37188^2 .

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1663375867) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 84912 + ... + 102648.

It is an arithmetic number, because the mean of its divisors is an integer number (70215873).

Almost surely, 2^1663375860 is an apocalyptic number.

1663375860 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 1663375860, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2527771428).

1663375860 is an abundant number, since it is smaller than the sum of its proper divisors (3392166996).

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

1663375860 is a wasteful number, since it uses less digits than its factorization.

1663375860 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18273 (or 18268 counting only the distinct ones).

The product of its (nonzero) digits is 544320, while the sum is 45.

The square root of 1663375860 is about 40784.5051459497. The cubic root of 1663375860 is about 1184.8502507986.

The spelling of 1663375860 in words is "one billion, six hundred sixty-three million, three hundred seventy-five thousand, eight hundred sixty".