161776645 has 8 divisors (see below), whose sum is σ = 200826360. Its totient is φ = 124958400.

The previous prime is 161776639. The next prime is 161776651. The reversal of 161776645 is 546677161.

It is an interprime number because it is at equal distance from previous prime (161776639) and next prime (161776651).

It can be written as a sum of positive squares in 4 ways, for example, as 2461761 + 159314884 = 1569^2 + 12622^2 .

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

It is not a de Polignac number, because 161776645 - 2¹⁵ = 161743877 is a prime.

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, 557706 + ... + 557995.

It is an arithmetic number, because the mean of its divisors is an integer number (25103295).

Almost surely, 2^161776645 is an apocalyptic number.

It is an amenable number.

161776645 is a deficient number, since it is larger than the sum of its proper divisors (39049715).

161776645 is a wasteful number, since it uses less digits than its factorization.

161776645 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1115735.

The product of its digits is 211680, while the sum is 43.

The square root of 161776645 is about 12719.1448218817. The cubic root of 161776645 is about 544.8855299245.

It can be divided in two parts, 16177 and 6645, that added together give a palindrome (22822).

The spelling of 161776645 in words is "one hundred sixty-one million, seven hundred seventy-six thousand, six hundred forty-five".