109787781 has 4 divisors (see below), whose sum is σ = 146383712. Its totient is φ = 73191852.

The previous prime is 109787779. The next prime is 109787789. The reversal of 109787781 is 187787901.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 109787781 - 2¹ = 109787779 is a prime.

It is a super-2 number, since 2×109787781² = 24106713713807922, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 109787781.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (109787789) 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, 18297961 + ... + 18297966.

It is an arithmetic number, because the mean of its divisors is an integer number (36595928).

Almost surely, 2^109787781 is an apocalyptic number.

It is an amenable number.

109787781 is a deficient number, since it is larger than the sum of its proper divisors (36595931).

109787781 is an equidigital number, since it uses as much as digits as its factorization.

109787781 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 36595930.

The product of its (nonzero) digits is 197568, while the sum is 48.

The square root of 109787781 is about 10477.9664534680. The cubic root of 109787781 is about 478.8336569355.

The spelling of 109787781 in words is "one hundred nine million, seven hundred eighty-seven thousand, seven hundred eighty-one".