81632223 has 12 divisors (see below), whose sum is σ = 119912520. Its totient is φ = 53498736.

The previous prime is 81632219. The next prime is 81632233. The reversal of 81632223 is 32223618.

81632223 is a `hidden beast` number, since 8 + 1 + 632 + 2 + 23 = 666.

It is not a de Polignac number, because 81632223 - 2² = 81632219 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81632233) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 76336 + ... + 77397.

It is an arithmetic number, because the mean of its divisors is an integer number (9992710).

Almost surely, 2^81632223 is an apocalyptic number.

81632223 is a deficient number, since it is larger than the sum of its proper divisors (38280297).

81632223 is a wasteful number, since it uses less digits than its factorization.

81632223 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 153798 (or 153795 counting only the distinct ones).

The product of its digits is 3456, while the sum is 27.

The square root of 81632223 is about 9035.0552294936. The cubic root of 81632223 is about 433.7976627661.

The spelling of 81632223 in words is "eighty-one million, six hundred thirty-two thousand, two hundred twenty-three".