109131981 has 16 divisors (see below), whose sum is σ = 170792064. Its totient is φ = 60675264.

The previous prime is 109131973. The next prime is 109131983. The reversal of 109131981 is 189131901.

It is a happy number.

It is not a de Polignac number, because 109131981 - 2³ = 109131973 is a prime.

It is a super-2 number, since 2×109131981² = 23819578553968722, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (109131983) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 69450 + ... + 71003.

It is an arithmetic number, because the mean of its divisors is an integer number (10674504).

Almost surely, 2^109131981 is an apocalyptic number.

It is an amenable number.

109131981 is a deficient number, since it is larger than the sum of its proper divisors (61660083).

109131981 is a wasteful number, since it uses less digits than its factorization.

109131981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 140500.

The product of its (nonzero) digits is 1944, while the sum is 33.

The square root of 109131981 is about 10446.6253402714. The cubic root of 109131981 is about 477.8783398063.

The spelling of 109131981 in words is "one hundred nine million, one hundred thirty-one thousand, nine hundred eighty-one".