165105261090 has 192 divisors, whose sum is σ = 553080648960. Its totient is φ = 34307539200.

The previous prime is 165105261049. The next prime is 165105261127. The reversal of 165105261090 is 90162501561.

165105261090 is a `hidden beast` number, since 1 + 6 + 510 + 52 + 6 + 1 + 0 + 90 = 666.

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 132291 + ... + 589670.

It is an arithmetic number, because the mean of its divisors is an integer number (2880628380).

Almost surely, 2^165105261090 is an apocalyptic number.

165105261090 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 165105261090, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (276540324480).

165105261090 is an abundant number, since it is smaller than the sum of its proper divisors (387975387870).

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

165105261090 is a wasteful number, since it uses less digits than its factorization.

165105261090 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 722006 (or 721989 counting only the distinct ones).

The product of its (nonzero) digits is 16200, while the sum is 36.

The spelling of 165105261090 in words is "one hundred sixty-five billion, one hundred five million, two hundred sixty-one thousand, ninety".