161966940 has 108 divisors (see below), whose sum is σ = 477617112. Its totient is φ = 41009280.

The previous prime is 161966929. The next prime is 161966941. The reversal of 161966940 is 49669161.

It is a junction number, because it is equal to n+sod(n) for n = 161966892 and 161966901.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161966941) by changing a digit.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 3055954 + ... + 3056006.

Almost surely, 2^161966940 is an apocalyptic number.

161966940 is a gapful number since it is divisible by the number (10) 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 161966940, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (238808556).

161966940 is an abundant number, since it is smaller than the sum of its proper divisors (315650172).

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

161966940 is a wasteful number, since it uses less digits than its factorization.

161966940 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 180 (or 94 counting only the distinct ones).

The product of its (nonzero) digits is 69984, while the sum is 42.

The square root of 161966940 is about 12726.6232756376. The cubic root of 161966940 is about 545.0990926066.

The spelling of 161966940 in words is "one hundred sixty-one million, nine hundred sixty-six thousand, nine hundred forty".