15661010105605 has 16 divisors (see below), whose sum is σ = 19903196619504. Its totient is φ = 11789151861760.

The previous prime is 15661010105597. The next prime is 15661010105623. The reversal of 15661010105605 is 50650101016651.

It can be written as a sum of positive squares in 8 ways, for example, as 1057980930724 + 14603029174881 = 1028582^2 + 3821391^2 .

It is not a de Polignac number, because 15661010105605 - 2³ = 15661010105597 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 20461942 + ... + 21213511.

It is an arithmetic number, because the mean of its divisors is an integer number (1243949788719).

Almost surely, 2^{15661010105605} is an apocalyptic number.

It is an amenable number.

15661010105605 is a deficient number, since it is larger than the sum of its proper divisors (4242186513899).

15661010105605 is a wasteful number, since it uses less digits than its factorization.

15661010105605 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 41679896.

The product of its (nonzero) digits is 27000, while the sum is 37.

The spelling of 15661010105605 in words is "fifteen trillion, six hundred sixty-one billion, ten million, one hundred five thousand, six hundred five".