16621552555 has 16 divisors (see below), whose sum is σ = 20095004160. Its totient is φ = 13198181472.

The previous prime is 16621552529. The next prime is 16621552639. The reversal of 16621552555 is 55525512661.

It is a cyclic number.

It is not a de Polignac number, because 16621552555 - 2⁵ = 16621552523 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 344212 + ... + 389518.

It is an arithmetic number, because the mean of its divisors is an integer number (1255937760).

Almost surely, 2^16621552555 is an apocalyptic number.

16621552555 is a deficient number, since it is larger than the sum of its proper divisors (3473451605).

16621552555 is a wasteful number, since it uses less digits than its factorization.

16621552555 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 45858.

The product of its digits is 450000, while the sum is 43.

The spelling of 16621552555 in words is "sixteen billion, six hundred twenty-one million, five hundred fifty-two thousand, five hundred fifty-five".