16400778 has 8 divisors (see below), whose sum is σ = 32801568. Its totient is φ = 5466924.

The previous prime is 16400737. The next prime is 16400789. The reversal of 16400778 is 87700461.

It is a sphenic number, since it is the product of 3 distinct primes.

16400778 is an admirable number.

It is a Smith number, since the sum of its digits (33) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1366726 + ... + 1366737.

It is an arithmetic number, because the mean of its divisors is an integer number (4100196).

Almost surely, 2^16400778 is an apocalyptic number.

16400778 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

16400778 is a wasteful number, since it uses less digits than its factorization.

16400778 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2733468.

The product of its (nonzero) digits is 9408, while the sum is 33.

The square root of 16400778 is about 4049.7874018274. The cubic root of 16400778 is about 254.0708360516.

The spelling of 16400778 in words is "sixteen million, four hundred thousand, seven hundred seventy-eight".