161720117395200 has 5184 divisors, whose sum is σ = 773355134103552. Its totient is φ = 32525726515200.

The previous prime is 161720117395171. The next prime is 161720117395223. The reversal of 161720117395200 is 2593711027161.

161720117395200 is a `hidden beast` number, since 1 + 6 + 1 + 7 + 2 + 0 + 117 + 3 + 9 + 520 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (5184).

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 575 ways as a sum of consecutive naturals, for example, 272715206104 + ... + 272715206696.

It is an arithmetic number, because the mean of its divisors is an integer number (149181160128).

Almost surely, 2^{161720117395200} is an apocalyptic number.

161720117395200 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 161720117395200, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (386677567051776).

161720117395200 is an abundant number, since it is smaller than the sum of its proper divisors (611635016708352).

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

161720117395200 is a wasteful number, since it uses less digits than its factorization.

161720117395200 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 742 (or 711 counting only the distinct ones).

The product of its (nonzero) digits is 158760, while the sum is 45.

The spelling of 161720117395200 in words is "one hundred sixty-one trillion, seven hundred twenty billion, one hundred seventeen million, three hundred ninety-five thousand, two hundred".