161722321200 has 240 divisors, whose sum is σ = 627940464000. Its totient is φ = 39205382400.

The previous prime is 161722321193. The next prime is 161722321207. The reversal of 161722321200 is 2123227161.

161722321200 is a `hidden beast` number, since 1 + 617 + 2 + 2 + 3 + 21 + 20 + 0 = 666.

It is an interprime number because it is at equal distance from previous prime (161722321193) and next prime (161722321207).

It is a tau number, because it is divible by the number of its divisors (240).

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

It is not an unprimeable number, because it can be changed into a prime (161722321207) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 561850 + ... + 799449.

It is an arithmetic number, because the mean of its divisors is an integer number (2616418600).

Almost surely, 2^161722321200 is an apocalyptic number.

161722321200 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

161722321200 is an abundant number, since it is smaller than the sum of its proper divisors (466218142800).

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

161722321200 is a wasteful number, since it uses less digits than its factorization.

161722321200 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1361337 (or 1361320 counting only the distinct ones).

The product of its (nonzero) digits is 2016, while the sum is 27.

Adding to 161722321200 its reverse (2123227161), we get a palindrome (163845548361).

The spelling of 161722321200 in words is "one hundred sixty-one billion, seven hundred twenty-two million, three hundred twenty-one thousand, two hundred".