109638561 has 4 divisors (see below), whose sum is σ = 146184752. Its totient is φ = 73092372.

The previous prime is 109638553. The next prime is 109638583. The reversal of 109638561 is 165836901.

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 109638561 - 2³ = 109638553 is a prime.

It is a super-2 number, since 2×109638561² = 24041228116301442, which contains 22 as substring.

It is an alternating number because its digits alternate between odd and even.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (109638761) 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, 18273091 + ... + 18273096.

It is an arithmetic number, because the mean of its divisors is an integer number (36546188).

Almost surely, 2^109638561 is an apocalyptic number.

It is an amenable number.

109638561 is a deficient number, since it is larger than the sum of its proper divisors (36546191).

109638561 is an equidigital number, since it uses as much as digits as its factorization.

109638561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 36546190.

The product of its (nonzero) digits is 38880, while the sum is 39.

The square root of 109638561 is about 10470.8433757745. The cubic root of 109638561 is about 478.6166201710.

The spelling of 109638561 in words is "one hundred nine million, six hundred thirty-eight thousand, five hundred sixty-one".