161808646 has 16 divisors (see below), whose sum is σ = 244721664. Its totient is φ = 80238024.

The previous prime is 161808641. The next prime is 161808677. The reversal of 161808646 is 646808161.

It is a junction number, because it is equal to n+sod(n) for n = 161808599 and 161808608.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161808641) 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, 148315 + ... + 149401.

It is an arithmetic number, because the mean of its divisors is an integer number (15295104).

Almost surely, 2^161808646 is an apocalyptic number.

161808646 is a deficient number, since it is larger than the sum of its proper divisors (82913018).

161808646 is a wasteful number, since it uses less digits than its factorization.

161808646 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1635.

The product of its (nonzero) digits is 55296, while the sum is 40.

The square root of 161808646 is about 12720.4027451964. The cubic root of 161808646 is about 544.9214554485.

The spelling of 161808646 in words is "one hundred sixty-one million, eight hundred eight thousand, six hundred forty-six".