161665110558 has 48 divisors (see below), whose sum is σ = 403000322400. Its totient is φ = 45880026048.

The previous prime is 161665110547. The next prime is 161665110569. The reversal of 161665110558 is 855011566161.

161665110558 is a `hidden beast` number, since 16 + 16 + 65 + 1 + 10 + 558 = 666.

It is an interprime number because it is at equal distance from previous prime (161665110547) and next prime (161665110569).

It is a super-3 number, since 3×161665110558³ (a number of 35 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 4286785 + ... + 4324332.

It is an arithmetic number, because the mean of its divisors is an integer number (8395840050).

Almost surely, 2^161665110558 is an apocalyptic number.

161665110558 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

161665110558 is an abundant number, since it is smaller than the sum of its proper divisors (241335211842).

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

161665110558 is a wasteful number, since it uses less digits than its factorization.

161665110558 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8611281 (or 8611278 counting only the distinct ones).

The product of its (nonzero) digits is 216000, while the sum is 45.

The spelling of 161665110558 in words is "one hundred sixty-one billion, six hundred sixty-five million, one hundred ten thousand, five hundred fifty-eight".