161772609 has 16 divisors (see below), whose sum is σ = 218625984. Its totient is φ = 106392000.

The previous prime is 161772581. The next prime is 161772613. The reversal of 161772609 is 906277161.

It is not a de Polignac number, because 161772609 - 2⁹ = 161772097 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (161772649) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 99487 + ... + 101099.

It is an arithmetic number, because the mean of its divisors is an integer number (13664124).

Almost surely, 2^161772609 is an apocalyptic number.

It is an amenable number.

161772609 is a deficient number, since it is larger than the sum of its proper divisors (56853375).

161772609 is a wasteful number, since it uses less digits than its factorization.

161772609 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2048.

The product of its (nonzero) digits is 31752, while the sum is 39.

The square root of 161772609 is about 12718.9861624266. The cubic root of 161772609 is about 544.8809986229.

The spelling of 161772609 in words is "one hundred sixty-one million, seven hundred seventy-two thousand, six hundred nine".