16557433475561 has 16 divisors (see below), whose sum is σ = 19128983042880. Its totient is φ = 14163958932480.

The previous prime is 16557433475537. The next prime is 16557433475567.

16557433475561 is nontrivially palindromic in base 10.

It is a cyclic number.

It is not a de Polignac number, because 16557433475561 - 2⁴² = 12159386964457 is a prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 16557433475494 and 16557433475503.

It is not an unprimeable number, because it can be changed into a prime (16557433475567) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 7901651 + ... + 9775016.

It is an arithmetic number, because the mean of its divisors is an integer number (1195561440180).

Almost surely, 2^{16557433475561} is an apocalyptic number.

16557433475561 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

16557433475561 is a deficient number, since it is larger than the sum of its proper divisors (2571549567319).

16557433475561 is a wasteful number, since it uses less digits than its factorization.

16557433475561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17681704.

The product of its digits is 158760000, while the sum is 62.

The spelling of 16557433475561 in words is "sixteen trillion, five hundred fifty-seven billion, four hundred thirty-three million, four hundred seventy-five thousand, five hundred sixty-one".