16650409 has 4 divisors (see below), whose sum is σ = 16673680. Its totient is φ = 16627140.

The previous prime is 16650397. The next prime is 16650433. The reversal of 16650409 is 90405661.

16650409 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 an emirpimes, since its reverse is a distinct semiprime: 90405661 = 257 ⋅351773.

It is a cyclic number.

It is not a de Polignac number, because 16650409 - 2¹³ = 16642217 is a prime.

It is a super-2 number, since 2×16650409² = 554472239734562, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (16650509) 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, 10527 + ... + 12004.

It is an arithmetic number, because the mean of its divisors is an integer number (4168420).

Almost surely, 2^16650409 is an apocalyptic number.

It is an amenable number.

16650409 is a deficient number, since it is larger than the sum of its proper divisors (23271).

16650409 is an equidigital number, since it uses as much as digits as its factorization.

16650409 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23270.

The product of its (nonzero) digits is 6480, while the sum is 31.

The square root of 16650409 is about 4080.4912694429. The cubic root of 16650409 is about 255.3533944218.

The spelling of 16650409 in words is "sixteen million, six hundred fifty thousand, four hundred nine".