16556440555 has 4 divisors (see below), whose sum is σ = 19867728672. Its totient is φ = 13245152440.

The previous prime is 16556440553. The next prime is 16556440559. The reversal of 16556440555 is 55504465561.

It is a happy number.

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

It is not a de Polignac number, because 16556440555 - 2¹ = 16556440553 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (16556440553) 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, 1655644051 + ... + 1655644060.

It is an arithmetic number, because the mean of its divisors is an integer number (4966932168).

Almost surely, 2^16556440555 is an apocalyptic number.

16556440555 is a deficient number, since it is larger than the sum of its proper divisors (3311288117).

16556440555 is an equidigital number, since it uses as much as digits as its factorization.

16556440555 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3311288116.

The product of its (nonzero) digits is 1800000, while the sum is 46.

The spelling of 16556440555 in words is "sixteen billion, five hundred fifty-six million, four hundred forty thousand, five hundred fifty-five".