161321785 has 8 divisors (see below), whose sum is σ = 194390856. Its totient is φ = 128520960.

The previous prime is 161321777. The next prime is 161321791. The reversal of 161321785 is 587123161.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 39175081 + 122146704 = 6259^2 + 11052^2 .

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

It is not a de Polignac number, because 161321785 - 2³ = 161321777 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 161321785.

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, 65734 + ... + 68143.

It is an arithmetic number, because the mean of its divisors is an integer number (24298857).

Almost surely, 2^161321785 is an apocalyptic number.

It is an amenable number.

161321785 is a deficient number, since it is larger than the sum of its proper divisors (33069071).

161321785 is a wasteful number, since it uses less digits than its factorization.

161321785 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 134123.

The product of its digits is 10080, while the sum is 34.

The square root of 161321785 is about 12701.2513163074. The cubic root of 161321785 is about 544.3743739785.

The spelling of 161321785 in words is "one hundred sixty-one million, three hundred twenty-one thousand, seven hundred eighty-five".