1781686368 has 480 divisors, whose sum is σ = 6674088960. Its totient is φ = 452874240.

The previous prime is 1781686349. The next prime is 1781686409. The reversal of 1781686368 is 8636861871.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a nude number because it is divisible by every one of its digits.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 79 ways as a sum of consecutive naturals, for example, 15767080 + ... + 15767192.

It is an arithmetic number, because the mean of its divisors is an integer number (13904352).

Almost surely, 2^1781686368 is an apocalyptic number.

1781686368 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 1781686368, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3337044480).

1781686368 is an abundant number, since it is smaller than the sum of its proper divisors (4892402592).

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

1781686368 is a wasteful number, since it uses less digits than its factorization.

1781686368 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 232 (or 215 counting only the distinct ones).

The product of its digits is 2322432, while the sum is 54.

The square root of 1781686368 is about 42210.0268656631. The cubic root of 1781686368 is about 1212.3008761892.

The spelling of 1781686368 in words is "one billion, seven hundred eighty-one million, six hundred eighty-six thousand, three hundred sixty-eight".