16404689 has 4 divisors (see below), whose sum is σ = 18748224. Its totient is φ = 14061156.

The previous prime is 16404679. The next prime is 16404709. The reversal of 16404689 is 98640461.

16404689 is digitally balanced in base 2 and base 8, because in such bases 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: 98640461 = 197 ⋅500713.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-16404689 is a prime.

It is a super-2 number, since 2×16404689² = 538227642373442, which contains 22 as substring.

It is a Duffinian number.

16404689 is strictly pandigital in base 8.

It is not an unprimeable number, because it can be changed into a prime (16404649) 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, 1171757 + ... + 1171770.

It is an arithmetic number, because the mean of its divisors is an integer number (4687056).

Almost surely, 2^16404689 is an apocalyptic number.

It is an amenable number.

16404689 is a deficient number, since it is larger than the sum of its proper divisors (2343535).

16404689 is an equidigital number, since it uses as much as digits as its factorization.

16404689 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2343534.

The product of its (nonzero) digits is 41472, while the sum is 38.

The square root of 16404689 is about 4050.2702378977. The cubic root of 16404689 is about 254.0910300543.

The spelling of 16404689 in words is "sixteen million, four hundred four thousand, six hundred eighty-nine".