163921605120 has 2400 divisors, whose sum is σ = 789440441328. Its totient is φ = 32105299968.

The previous prime is 163921605083. The next prime is 163921605139. The reversal of 163921605120 is 21506129361.

163921605120 is a `hidden beast` number, since 1 + 6 + 3 + 9 + 21 + 605 + 1 + 20 = 666.

It can be written as a sum of positive squares in 8 ways, for example, as 68158589184 + 95763015936 = 261072^2 + 309456^2 .

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 239 ways as a sum of consecutive naturals, for example, 2245501404 + ... + 2245501476.

Almost surely, 2^163921605120 is an apocalyptic number.

163921605120 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 163921605120, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (394720220664).

163921605120 is an abundant number, since it is smaller than the sum of its proper divisors (625518836208).

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

163921605120 is a wasteful number, since it uses less digits than its factorization.

163921605120 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 152 (or 120 counting only the distinct ones).

The product of its (nonzero) digits is 19440, while the sum is 36.

The spelling of 163921605120 in words is "one hundred sixty-three billion, nine hundred twenty-one million, six hundred five thousand, one hundred twenty".