109617821 has 4 divisors (see below), whose sum is σ = 115387200. Its totient is φ = 103848444.

The previous prime is 109617803. The next prime is 109617863. The reversal of 109617821 is 128716901.

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 a cyclic number.

It is not a de Polignac number, because 109617821 - 2¹⁰ = 109616797 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (109617881) 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, 2884661 + ... + 2884698.

It is an arithmetic number, because the mean of its divisors is an integer number (28846800).

Almost surely, 2^109617821 is an apocalyptic number.

It is an amenable number.

109617821 is a deficient number, since it is larger than the sum of its proper divisors (5769379).

109617821 is an equidigital number, since it uses as much as digits as its factorization.

109617821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5769378.

The product of its (nonzero) digits is 6048, while the sum is 35.

The square root of 109617821 is about 10469.8529598080. The cubic root of 109617821 is about 478.5864387743.

The spelling of 109617821 in words is "one hundred nine million, six hundred seventeen thousand, eight hundred twenty-one".