109856891 has 4 divisors (see below), whose sum is σ = 111180552. Its totient is φ = 108533232.

The previous prime is 109856867. The next prime is 109856899. The reversal of 109856891 is 198658901.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 198658901 = 7 ⋅28379843.

It is a cyclic number.

It is not a de Polignac number, because 109856891 - 2⁶ = 109856827 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (109856899) 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 3 ways as a sum of consecutive naturals, for example, 661706 + ... + 661871.

It is an arithmetic number, because the mean of its divisors is an integer number (27795138).

Almost surely, 2^109856891 is an apocalyptic number.

109856891 is a deficient number, since it is larger than the sum of its proper divisors (1323661).

109856891 is an equidigital number, since it uses as much as digits as its factorization.

109856891 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1323660.

The product of its (nonzero) digits is 155520, while the sum is 47.

The square root of 109856891 is about 10481.2638073851. The cubic root of 109856891 is about 478.9341090758.

The spelling of 109856891 in words is "one hundred nine million, eight hundred fifty-six thousand, eight hundred ninety-one".