109609821 has 16 divisors (see below), whose sum is σ = 167985600. Its totient is φ = 70552944.

The previous prime is 109609807. The next prime is 109609823. The reversal of 109609821 is 128906901.

It is not a de Polignac number, because 109609821 - 2¹⁰ = 109608797 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (109609823) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 69211 + ... + 70776.

It is an arithmetic number, because the mean of its divisors is an integer number (10499100).

Almost surely, 2^109609821 is an apocalyptic number.

It is an amenable number.

109609821 is a deficient number, since it is larger than the sum of its proper divisors (58375779).

109609821 is a wasteful number, since it uses less digits than its factorization.

109609821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 140025 (or 140019 counting only the distinct ones).

The product of its (nonzero) digits is 7776, while the sum is 36.

The square root of 109609821 is about 10469.4709035366. The cubic root of 109609821 is about 478.5747959453.

The spelling of 109609821 in words is "one hundred nine million, six hundred nine thousand, eight hundred twenty-one".