81888985 has 8 divisors (see below), whose sum is σ = 100552320. Its totient is φ = 63987504.

The previous prime is 81888973. The next prime is 81889007. The reversal of 81888985 is 58988818.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 81888985 - 2¹⁹ = 81364697 is a prime.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 190225 + ... + 190654.

It is an arithmetic number, because the mean of its divisors is an integer number (12569040).

Almost surely, 2^81888985 is an apocalyptic number.

It is an amenable number.

81888985 is a deficient number, since it is larger than the sum of its proper divisors (18663335).

81888985 is a wasteful number, since it uses less digits than its factorization.

81888985 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 380927.

The product of its digits is 1474560, while the sum is 55.

The square root of 81888985 is about 9049.2532841113. The cubic root of 81888985 is about 434.2520020607.

The spelling of 81888985 in words is "eighty-one million, eight hundred eighty-eight thousand, nine hundred eighty-five".