109139809 has 9 divisors (see below), whose sum is σ = 113109651. Its totient is φ = 105305760.

The previous prime is 109139803. The next prime is 109139837. The reversal of 109139809 is 908931901.

The square root of 109139809 is 10447.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 29430625 + 79709184 = 5425^2 + 8928^2 .

It is not a de Polignac number, because 109139809 - 2³ = 109139801 is a prime.

It is a super-2 number, since 2×109139809² = 23822995817112962, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (109139801) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 323689 + ... + 324025.

It is an arithmetic number, because the mean of its divisors is an integer number (12567739).

Almost surely, 2^109139809 is an apocalyptic number.

109139809 is the 10447-th square number.

109139809 is the 5224-th centered octagonal number.

It is an amenable number.

109139809 is a deficient number, since it is larger than the sum of its proper divisors (3969842).

109139809 is an frugal number, since it uses more digits than its factorization.

109139809 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 736 (or 368 counting only the distinct ones).

The product of its (nonzero) digits is 17496, while the sum is 40.

The cubic root of 109139809 is about 477.8897655502.

The spelling of 109139809 in words is "one hundred nine million, one hundred thirty-nine thousand, eight hundred nine".