16400555 has 4 divisors (see below), whose sum is σ = 19680672. Its totient is φ = 13120440.

The previous prime is 16400539. The next prime is 16400567. The reversal of 16400555 is 55500461.

16400555 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.

It is not a de Polignac number, because 16400555 - 2⁴ = 16400539 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1640051 + ... + 1640060.

It is an arithmetic number, because the mean of its divisors is an integer number (4920168).

Almost surely, 2^16400555 is an apocalyptic number.

16400555 is a deficient number, since it is larger than the sum of its proper divisors (3280117).

16400555 is an equidigital number, since it uses as much as digits as its factorization.

16400555 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3280116.

The product of its (nonzero) digits is 3000, while the sum is 26.

The square root of 16400555 is about 4049.7598694244. The cubic root of 16400555 is about 254.0696845198.

The spelling of 16400555 in words is "sixteen million, four hundred thousand, five hundred fifty-five".