161537435539866 has 16 divisors (see below), whose sum is σ = 358972078977600. Its totient is φ = 53845811846604.

The previous prime is 161537435539861. The next prime is 161537435539889. The reversal of 161537435539866 is 668935534735161.

161537435539866 is a `hidden beast` number, since 1 + 6 + 1 + 5 + 3 + 7 + 4 + 3 + 5 + 539 + 86 + 6 = 666.

It is a junction number, because it is equal to n+sod(n) for n = 161537435539794 and 161537435539803.

It is not an unprimeable number, because it can be changed into a prime (161537435539861) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1495716995686 + ... + 1495716995793.

It is an arithmetic number, because the mean of its divisors is an integer number (22435754936100).

Almost surely, 2^{161537435539866} is an apocalyptic number.

161537435539866 is an abundant number, since it is smaller than the sum of its proper divisors (197434643437734).

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

161537435539866 is a wasteful number, since it uses less digits than its factorization.

161537435539866 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2991433991490 (or 2991433991484 counting only the distinct ones).

The product of its digits is 1469664000, while the sum is 72.

The spelling of 161537435539866 in words is "one hundred sixty-one trillion, five hundred thirty-seven billion, four hundred thirty-five million, five hundred thirty-nine thousand, eight hundred sixty-six".