161765031209 has 8 divisors (see below), whose sum is σ = 170315127840. Its totient is φ = 153218549376.

The previous prime is 161765031199. The next prime is 161765031223. The reversal of 161765031209 is 902130567161.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-161765031209 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (161765031229) 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, 811592 + ... + 991065.

It is an arithmetic number, because the mean of its divisors is an integer number (21289390980).

Almost surely, 2^161765031209 is an apocalyptic number.

161765031209 is a gapful number since it is divisible by the number (19) formed by its first and last digit.

It is an amenable number.

161765031209 is a deficient number, since it is larger than the sum of its proper divisors (8550096631).

161765031209 is a wasteful number, since it uses less digits than its factorization.

161765031209 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1807399.

The product of its (nonzero) digits is 68040, while the sum is 41.

The spelling of 161765031209 in words is "one hundred sixty-one billion, seven hundred sixty-five million, thirty-one thousand, two hundred nine".