161561561606 has 8 divisors (see below), whose sum is σ = 252878966064. Its totient is φ = 77268572920.

The previous prime is 161561561593. The next prime is 161561561639. The reversal of 161561561606 is 606165165161.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a super-2 number, since 2×161561561606² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1756103885 + ... + 1756103976.

It is an arithmetic number, because the mean of its divisors is an integer number (31609870758).

Almost surely, 2^161561561606 is an apocalyptic number.

161561561606 is a deficient number, since it is larger than the sum of its proper divisors (91317404458).

161561561606 is a wasteful number, since it uses less digits than its factorization.

161561561606 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3512207886.

The product of its (nonzero) digits is 194400, while the sum is 44.

The spelling of 161561561606 in words is "one hundred sixty-one billion, five hundred sixty-one million, five hundred sixty-one thousand, six hundred six".