16553909 has 4 divisors (see below), whose sum is σ = 16562304. Its totient is φ = 16545516.

The previous prime is 16553893. The next prime is 16553941. The reversal of 16553909 is 90935561.

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, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 90935561 = 29 ⋅3135709.

It is a cyclic number.

It is not a de Polignac number, because 16553909 - 2⁴ = 16553893 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 (16553989) 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, 554 + ... + 5780.

It is an arithmetic number, because the mean of its divisors is an integer number (4140576).

Almost surely, 2^16553909 is an apocalyptic number.

It is an amenable number.

16553909 is a deficient number, since it is larger than the sum of its proper divisors (8395).

16553909 is an equidigital number, since it uses as much as digits as its factorization.

16553909 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8394.

The product of its (nonzero) digits is 36450, while the sum is 38.

The square root of 16553909 is about 4068.6495302496. The cubic root of 16553909 is about 254.8591250586.

The spelling of 16553909 in words is "sixteen million, five hundred fifty-three thousand, nine hundred nine".