16555455509 has 2 divisors, whose sum is σ = 16555455510. Its totient is φ = 16555455508.

The previous prime is 16555455493. The next prime is 16555455541. The reversal of 16555455509 is 90555455561.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 15443032900 + 1112422609 = 124270^2 + 33353^2 .

It is a cyclic number.

It is not a de Polignac number, because 16555455509 - 2⁴ = 16555455493 is a prime.

It is a super-2 number, since 2×16555455509² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (16555455589) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8277727754 + 8277727755.

It is an arithmetic number, because the mean of its divisors is an integer number (8277727755).

Almost surely, 2^16555455509 is an apocalyptic number.

It is an amenable number.

16555455509 is a deficient number, since it is larger than the sum of its proper divisors (1).

16555455509 is an equidigital number, since it uses as much as digits as its factorization.

16555455509 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3375000, while the sum is 50.

The spelling of 16555455509 in words is "sixteen billion, five hundred fifty-five million, four hundred fifty-five thousand, five hundred nine".