161637944580 has 480 divisors, whose sum is σ = 587202739200. Its totient is φ = 36458864640.

The previous prime is 161637944569. The next prime is 161637944593. The reversal of 161637944580 is 85449736161.

161637944580 is a `hidden beast` number, since 1 + 6 + 16 + 3 + 7 + 9 + 44 + 580 = 666.

It is a super-2 number, since 2×161637944580² (a number of 23 digits) contains 22 as substring.

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

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 159 ways as a sum of consecutive naturals, for example, 457897684 + ... + 457898036.

It is an arithmetic number, because the mean of its divisors is an integer number (1223339040).

Almost surely, 2^161637944580 is an apocalyptic number.

161637944580 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 161637944580, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (293601369600).

161637944580 is an abundant number, since it is smaller than the sum of its proper divisors (425564794620).

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

161637944580 is a wasteful number, since it uses less digits than its factorization.

161637944580 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 801 (or 790 counting only the distinct ones).

The product of its (nonzero) digits is 4354560, while the sum is 54.

The spelling of 161637944580 in words is "one hundred sixty-one billion, six hundred thirty-seven million, nine hundred forty-four thousand, five hundred eighty".