161556909696 has 1024 divisors, whose sum is σ = 616786329600. Its totient is φ = 40489943040.

The previous prime is 161556909641. The next prime is 161556909707. The reversal of 161556909696 is 696909655161.

161556909696 is a `hidden beast` number, since 1 + 6 + 1 + 5 + 569 + 0 + 9 + 69 + 6 = 666.

It is a super-2 number, since 2×161556909696² (a number of 23 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (63).

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 127 ways as a sum of consecutive naturals, for example, 711704335 + ... + 711704561.

It is an arithmetic number, because the mean of its divisors is an integer number (602330400).

Almost surely, 2^161556909696 is an apocalyptic number.

161556909696 is a gapful number since it is divisible by the number (16) 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 161556909696, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (308393164800).

161556909696 is an abundant number, since it is smaller than the sum of its proper divisors (455229419904).

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

161556909696 is a wasteful number, since it uses less digits than its factorization.

161556909696 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 374 (or 356 counting only the distinct ones).

The product of its (nonzero) digits is 23619600, while the sum is 63.

The spelling of 161556909696 in words is "one hundred sixty-one billion, five hundred fifty-six million, nine hundred nine thousand, six hundred ninety-six".