99831981 has 8 divisors (see below), whose sum is σ = 133161120. Its totient is φ = 66528752.

The previous prime is 99831967. The next prime is 99832001. The reversal of 99831981 is 18913899.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-99831981 is a prime.

It is a super-2 number, since 2×99831981² = 19932848860768722, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 99831981.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (99831911) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5890 + ... + 15308.

It is an arithmetic number, because the mean of its divisors is an integer number (16645140).

Almost surely, 2^99831981 is an apocalyptic number.

It is an amenable number.

99831981 is a deficient number, since it is larger than the sum of its proper divisors (33329139).

99831981 is a wasteful number, since it uses less digits than its factorization.

99831981 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12955.

The product of its digits is 139968, while the sum is 48.

The square root of 99831981 is about 9991.5955182343. The cubic root of 99831981 is about 463.8987792607.

The spelling of 99831981 in words is "ninety-nine million, eight hundred thirty-one thousand, nine hundred eighty-one".