99881681 has 8 divisors (see below), whose sum is σ = 105855840. Its totient is φ = 93918528.

The previous prime is 99881671. The next prime is 99881687. The reversal of 99881681 is 18618899.

It is a happy number.

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 99881681 - 2¹⁰ = 99880657 is a prime.

It is a super-2 number, since 2×99881681² = 19952700398771522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (99881687) by changing a digit.

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, 22790 + ... + 26816.

It is an arithmetic number, because the mean of its divisors is an integer number (13231980).

Almost surely, 2^99881681 is an apocalyptic number.

It is an amenable number.

99881681 is a deficient number, since it is larger than the sum of its proper divisors (5974159).

99881681 is a wasteful number, since it uses less digits than its factorization.

99881681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5503.

The product of its digits is 248832, while the sum is 50.

The square root of 99881681 is about 9994.0822990408. The cubic root of 99881681 is about 463.9757483981.

The spelling of 99881681 in words is "ninety-nine million, eight hundred eighty-one thousand, six hundred eighty-one".