109991971 has 4 divisors (see below), whose sum is σ = 112674744. Its totient is φ = 107309200.

The previous prime is 109991933. The next prime is 109991977. The reversal of 109991971 is 179199901.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 179199901 = 223 ⋅803587.

It is a cyclic number.

It is not a de Polignac number, because 109991971 - 2⁹ = 109991459 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (109991977) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1341325 + ... + 1341406.

It is an arithmetic number, because the mean of its divisors is an integer number (28168686).

Almost surely, 2^109991971 is an apocalyptic number.

109991971 is a deficient number, since it is larger than the sum of its proper divisors (2682773).

109991971 is an equidigital number, since it uses as much as digits as its factorization.

109991971 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2682772.

The product of its (nonzero) digits is 45927, while the sum is 46.

The square root of 109991971 is about 10487.7057071602. The cubic root of 109991971 is about 479.1303277529.

The spelling of 109991971 in words is "one hundred nine million, nine hundred ninety-one thousand, nine hundred seventy-one".