16406399 has 4 divisors (see below), whose sum is σ = 16428720. Its totient is φ = 16384080.

The previous prime is 16406393. The next prime is 16406407. The reversal of 16406399 is 99360461.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 99360461 = 17 ⋅5844733.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-16406399 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 (16406393) 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, 10019 + ... + 11540.

It is an arithmetic number, because the mean of its divisors is an integer number (4107180).

Almost surely, 2^16406399 is an apocalyptic number.

16406399 is a deficient number, since it is larger than the sum of its proper divisors (22321).

16406399 is an equidigital number, since it uses as much as digits as its factorization.

16406399 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22320.

The product of its (nonzero) digits is 34992, while the sum is 38.

The square root of 16406399 is about 4050.4813294225. The cubic root of 16406399 is about 254.0998584360.

The spelling of 16406399 in words is "sixteen million, four hundred six thousand, three hundred ninety-nine".