161320723200 has 864 divisors, whose sum is σ = 728128396800. Its totient is φ = 34033582080.

The previous prime is 161320723181. The next prime is 161320723229. The reversal of 161320723200 is 2327023161.

161320723200 is a `hidden beast` number, since 1 + 613 + 2 + 0 + 7 + 23 + 20 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (864).

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 15719671 + ... + 15729929.

It is an arithmetic number, because the mean of its divisors is an integer number (842741200).

Almost surely, 2^161320723200 is an apocalyptic number.

161320723200 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 161320723200, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (364064198400).

161320723200 is an abundant number, since it is smaller than the sum of its proper divisors (566807673600).

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

161320723200 is a wasteful number, since it uses less digits than its factorization.

161320723200 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10314 (or 10289 counting only the distinct ones).

The product of its (nonzero) digits is 3024, while the sum is 27.

Adding to 161320723200 its reverse (2327023161), we get a palindrome (163647746361).

The spelling of 161320723200 in words is "one hundred sixty-one billion, three hundred twenty million, seven hundred twenty-three thousand, two hundred".