181581663376 has 15 divisors (see below), whose sum is σ = 351817775283. Its totient is φ = 90789979440.

The previous prime is 181581663371. The next prime is 181581663463. The reversal of 181581663376 is 673366185181.

It is a happy number.

The square root of 181581663376 is 426124.

It is a perfect power (a square), and thus also a powerful number.

181581663376 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (181581663371) by changing a digit.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 1651231 + ... + 1757761.

Almost surely, 2^181581663376 is an apocalyptic number.

181581663376 is a gapful number since it is divisible by the number (16) formed by its first and last digit.

181581663376 is the 426124-th square number.

It is an amenable number.

181581663376 is a deficient number, since it is larger than the sum of its proper divisors (170236111907).

181581663376 is an frugal number, since it uses more digits than its factorization.

181581663376 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 213070 (or 106533 counting only the distinct ones).

The product of its digits is 4354560, while the sum is 55.

The spelling of 181581663376 in words is "one hundred eighty-one billion, five hundred eighty-one million, six hundred sixty-three thousand, three hundred seventy-six".