161712921600 has 1584 divisors, whose sum is σ = 673547827680. Its totient is φ = 36805017600.

The previous prime is 161712921577. The next prime is 161712921607. The reversal of 161712921600 is 6129217161.

161712921600 is a `hidden beast` number, since 1 + 6 + 1 + 7 + 1 + 29 + 21 + 600 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161712921607) by changing a digit.

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 143 ways as a sum of consecutive naturals, for example, 3051187174 + ... + 3051187226.

Almost surely, 2^161712921600 is an apocalyptic number.

161712921600 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 161712921600, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (336773913840).

161712921600 is an abundant number, since it is smaller than the sum of its proper divisors (511834906080).

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

161712921600 is a wasteful number, since it uses less digits than its factorization.

161712921600 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 166 (or 140 counting only the distinct ones).

The product of its (nonzero) digits is 9072, while the sum is 36.

The spelling of 161712921600 in words is "one hundred sixty-one billion, seven hundred twelve million, nine hundred twenty-one thousand, six hundred".