161530644 has 72 divisors (see below), whose sum is σ = 422301600. Its totient is φ = 48002240.

The previous prime is 161530631. The next prime is 161530669. The reversal of 161530644 is 446035161.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 75907 + ... + 78005.

It is an arithmetic number, because the mean of its divisors is an integer number (5865300).

Almost surely, 2^161530644 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 161530644, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (211150800).

161530644 is an abundant number, since it is smaller than the sum of its proper divisors (260770956).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

161530644 is a wasteful number, since it uses less digits than its factorization.

161530644 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2181 (or 2168 counting only the distinct ones).

The product of its (nonzero) digits is 8640, while the sum is 30.

The square root of 161530644 is about 12709.4706420055. The cubic root of 161530644 is about 544.6092016463.

The spelling of 161530644 in words is "one hundred sixty-one million, five hundred thirty thousand, six hundred forty-four".