111099981 has 24 divisors (see below), whose sum is σ = 158755840. Its totient is φ = 69092352.

The previous prime is 111099979. The next prime is 111099983. The reversal of 111099981 is 189990111.

It is an interprime number because it is at equal distance from previous prime (111099979) and next prime (111099983).

It is not a de Polignac number, because 111099981 - 2¹ = 111099979 is a prime.

It is a super-2 number, since 2×111099981² = 24686411556400722, which contains 22 as substring.

It is a Smith number, since the sum of its digits (39) coincides with the sum of the digits of its prime factors.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (111099983) 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 23 ways as a sum of consecutive naturals, for example, 109605 + ... + 110613.

Almost surely, 2^111099981 is an apocalyptic number.

It is an amenable number.

111099981 is a deficient number, since it is larger than the sum of its proper divisors (47655859).

111099981 is a wasteful number, since it uses less digits than its factorization.

111099981 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1173 (or 1156 counting only the distinct ones).

The product of its (nonzero) digits is 5832, while the sum is 39.

The square root of 111099981 is about 10540.3975731468. The cubic root of 111099981 is about 480.7338038351.

The spelling of 111099981 in words is "one hundred eleven million, ninety-nine thousand, nine hundred eighty-one".