16553501463561 has 4 divisors (see below), whose sum is σ = 22071335284752. Its totient is φ = 11035667642372.

The previous prime is 16553501463559. The next prime is 16553501463607. The reversal of 16553501463561 is 16536410535561.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 16553501463561 - 2¹ = 16553501463559 is a prime.

It is not an unprimeable number, because it can be changed into a prime (16553501463061) 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, 2758916910591 + ... + 2758916910596.

It is an arithmetic number, because the mean of its divisors is an integer number (5517833821188).

Almost surely, 2^{16553501463561} is an apocalyptic number.

It is an amenable number.

16553501463561 is a deficient number, since it is larger than the sum of its proper divisors (5517833821191).

16553501463561 is an equidigital number, since it uses as much as digits as its factorization.

16553501463561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5517833821190.

The product of its (nonzero) digits is 4860000, while the sum is 51.

The spelling of 16553501463561 in words is "sixteen trillion, five hundred fifty-three billion, five hundred one million, four hundred sixty-three thousand, five hundred sixty-one".