161985600 has 252 divisors, whose sum is σ = 658392384. Its totient is φ = 37002240.

The previous prime is 161985599. The next prime is 161985631. The reversal of 161985600 is 6589161.

161985600 is a `hidden beast` number, since 1 + 6 + 1 + 98 + 560 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (252).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is an unprimeable number.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 99997 + ... + 101603.

Almost surely, 2^161985600 is an apocalyptic number.

161985600 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 161985600, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (329196192).

161985600 is an abundant number, since it is smaller than the sum of its proper divisors (496406784).

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

161985600 is a wasteful number, since it uses less digits than its factorization.

161985600 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1642 (or 1624 counting only the distinct ones).

The product of its (nonzero) digits is 12960, while the sum is 36.

The square root of 161985600 is about 12727.3563633616. The cubic root of 161985600 is about 545.1200251880.

The spelling of 161985600 in words is "one hundred sixty-one million, nine hundred eighty-five thousand, six hundred".