161481978432 has 280 divisors, whose sum is σ = 501207121536. Its totient is φ = 51310651392.

The previous prime is 161481978403. The next prime is 161481978433. The reversal of 161481978432 is 234879184161.

161481978432 is a `hidden beast` number, since 1 + 6 + 14 + 8 + 197 + 8 + 432 = 666.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is not an unprimeable number, because it can be changed into a prime (161481978433) by changing a digit.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 37317453 + ... + 37321779.

Almost surely, 2^161481978432 is an apocalyptic number.

161481978432 is a gapful number since it is divisible by the number (12) 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 161481978432, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (250603560768).

161481978432 is an abundant number, since it is smaller than the sum of its proper divisors (339725143104).

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

161481978432 is a wasteful number, since it uses less digits than its factorization.

161481978432 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4687 (or 4668 counting only the distinct ones).

The product of its digits is 2322432, while the sum is 54.

The spelling of 161481978432 in words is "one hundred sixty-one billion, four hundred eighty-one million, nine hundred seventy-eight thousand, four hundred thirty-two".