161861027165 has 8 divisors (see below), whose sum is σ = 194237152728. Its totient is φ = 129486208320.

The previous prime is 161861027129. The next prime is 161861027177. The reversal of 161861027165 is 561720168161.

It can be written as a sum of positive squares in 4 ways, for example, as 22364006116 + 139497021049 = 149546^2 + 373493^2 .

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

It is not a de Polignac number, because 161861027165 - 2¹⁰ = 161861026141 is a prime.

It is a super-2 number, since 2×161861027165² (a number of 23 digits) contains 22 as substring.

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 7 ways as a sum of consecutive naturals, for example, 29606 + ... + 569735.

It is an arithmetic number, because the mean of its divisors is an integer number (24279644091).

Almost surely, 2^161861027165 is an apocalyptic number.

It is an amenable number.

161861027165 is a deficient number, since it is larger than the sum of its proper divisors (32376125563).

161861027165 is an equidigital number, since it uses as much as digits as its factorization.

161861027165 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 653359.

The product of its (nonzero) digits is 120960, while the sum is 44.

The spelling of 161861027165 in words is "one hundred sixty-one billion, eight hundred sixty-one million, twenty-seven thousand, one hundred sixty-five".