161961696 has 144 divisors (see below), whose sum is σ = 500834880. Its totient is φ = 49351680.

The previous prime is 161961689. The next prime is 161961739. The reversal of 161961696 is 696169161.

161961696 is a `hidden beast` number, since 16 + 19 + 616 + 9 + 6 = 666.

161961696 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a tau number, because it is divible by the number of its divisors (144).

It is a nude number because it is divisible by every one of its digits.

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, 677545 + ... + 677783.

It is an arithmetic number, because the mean of its divisors is an integer number (3478020).

Almost surely, 2^161961696 is an apocalyptic number.

161961696 is a gapful number since it is divisible by the number (16) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 161961696, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (250417440).

161961696 is an abundant number, since it is smaller than the sum of its proper divisors (338873184).

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

161961696 is a wasteful number, since it uses less digits than its factorization.

161961696 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 449 (or 438 counting only the distinct ones).

The product of its digits is 104976, while the sum is 45.

The square root of 161961696 is about 12726.4172491711. The cubic root of 161961696 is about 545.0932096560.

The spelling of 161961696 in words is "one hundred sixty-one million, nine hundred sixty-one thousand, six hundred ninety-six".