161912131200 has 960 divisors, whose sum is σ = 622876056000. Its totient is φ = 41385738240.

The previous prime is 161912131103. The next prime is 161912131319. The reversal of 161912131200 is 2131219161.

It is a happy number.

161912131200 is a `hidden beast` number, since 1 + 619 + 1 + 21 + 3 + 1 + 20 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (960).

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

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 119 ways as a sum of consecutive naturals, for example, 813628701 + ... + 813628899.

It is an arithmetic number, because the mean of its divisors is an integer number (648829225).

Almost surely, 2^161912131200 is an apocalyptic number.

161912131200 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 161912131200, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (311438028000).

161912131200 is an abundant number, since it is smaller than the sum of its proper divisors (460963924800).

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

161912131200 is a wasteful number, since it uses less digits than its factorization.

161912131200 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 351 (or 325 counting only the distinct ones).

The product of its (nonzero) digits is 648, while the sum is 27.

The spelling of 161912131200 in words is "one hundred sixty-one billion, nine hundred twelve million, one hundred thirty-one thousand, two hundred".