16923509 has 4 divisors (see below), whose sum is σ = 17814240. Its totient is φ = 16032780.

The previous prime is 16923481. The next prime is 16923521. The reversal of 16923509 is 90532961.

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 16923509 - 2⁸ = 16923253 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 (16923539) 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, 445337 + ... + 445374.

It is an arithmetic number, because the mean of its divisors is an integer number (4453560).

Almost surely, 2^16923509 is an apocalyptic number.

16923509 is a gapful number since it is divisible by the number (19) formed by its first and last digit.

It is an amenable number.

16923509 is a deficient number, since it is larger than the sum of its proper divisors (890731).

16923509 is an equidigital number, since it uses as much as digits as its factorization.

16923509 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 890730.

The product of its (nonzero) digits is 14580, while the sum is 35.

The square root of 16923509 is about 4113.8192716744. The cubic root of 16923509 is about 256.7419323504.

The spelling of 16923509 in words is "sixteen million, nine hundred twenty-three thousand, five hundred nine".