109439991 has 10 divisors (see below), whose sum is σ = 163484552. Its totient is φ = 72959940.

The previous prime is 109439989. The next prime is 109440041. The reversal of 109439991 is 199934901.

It is not a de Polignac number, because 109439991 - 2¹ = 109439989 is a prime.

It is a super-2 number, since 2×109439991² = 23954223260160162, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (109439971) by changing a digit.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 675475 + ... + 675636.

Almost surely, 2^109439991 is an apocalyptic number.

109439991 is a deficient number, since it is larger than the sum of its proper divisors (54044561).

109439991 is an equidigital number, since it uses as much as digits as its factorization.

109439991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1351123 (or 1351114 counting only the distinct ones).

The product of its (nonzero) digits is 78732, while the sum is 45.

The square root of 109439991 is about 10461.3570343431. The cubic root of 109439991 is about 478.3274994601.

The spelling of 109439991 in words is "one hundred nine million, four hundred thirty-nine thousand, nine hundred ninety-one".