15661561542546 has 16 divisors (see below), whose sum is σ = 31323164040000. Its totient is φ = 5220513688368.

The previous prime is 15661561542521. The next prime is 15661561542551. The reversal of 15661561542546 is 64524516516651.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5815080 + ... + 8070828.

It is an arithmetic number, because the mean of its divisors is an integer number (1957697752500).

Almost surely, 2^{15661561542546} is an apocalyptic number.

15661561542546 is an abundant number, since it is smaller than the sum of its proper divisors (15661602497454).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

15661561542546 is a wasteful number, since it uses less digits than its factorization.

15661561542546 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3412913.

The product of its digits is 25920000, while the sum is 57.

The spelling of 15661561542546 in words is "fifteen trillion, six hundred sixty-one billion, five hundred sixty-one million, five hundred forty-two thousand, five hundred forty-six".