16561106542 has 4 divisors (see below), whose sum is σ = 24841659816. Its totient is φ = 8280553270.

The previous prime is 16561106519. The next prime is 16561106557. The reversal of 16561106542 is 24560116561.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 24560116561 = 13007 ⋅1888223.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4140276634 + ... + 4140276637.

It is an arithmetic number, because the mean of its divisors is an integer number (6210414954).

Almost surely, 2^16561106542 is an apocalyptic number.

16561106542 is a deficient number, since it is larger than the sum of its proper divisors (8280553274).

16561106542 is an equidigital number, since it uses as much as digits as its factorization.

16561106542 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8280553273.

The product of its (nonzero) digits is 43200, while the sum is 37.

The spelling of 16561106542 in words is "sixteen billion, five hundred sixty-one million, one hundred six thousand, five hundred forty-two".