16400999 has 4 divisors (see below), whose sum is σ = 16560336. Its totient is φ = 16241664.

The previous prime is 16400987. The next prime is 16401013. The reversal of 16400999 is 99900461.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 16400999 - 2¹² = 16396903 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 (16400939) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 79514 + ... + 79719.

It is an arithmetic number, because the mean of its divisors is an integer number (4140084).

Almost surely, 2^16400999 is an apocalyptic number.

16400999 is a deficient number, since it is larger than the sum of its proper divisors (159337).

16400999 is a wasteful number, since it uses less digits than its factorization.

16400999 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 159336.

The product of its (nonzero) digits is 17496, while the sum is 38.

The square root of 16400999 is about 4049.8146871184. The cubic root of 16400999 is about 254.0719772455.

The spelling of 16400999 in words is "sixteen million, four hundred thousand, nine hundred ninety-nine".