161966488878 has 24 divisors (see below), whose sum is σ = 351112068216. Its totient is φ = 53960418000.

The previous prime is 161966488843. The next prime is 161966488909. The reversal of 161966488878 is 878884669161.

161966488878 is a `hidden beast` number, since 1 + 6 + 1 + 9 + 66 + 488 + 87 + 8 = 666.

It is a super-3 number, since 3×161966488878³ (a number of 35 digits) contains 333 as substring.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2332468 + ... + 2400903.

It is an arithmetic number, because the mean of its divisors is an integer number (14629669509).

Almost surely, 2^161966488878 is an apocalyptic number.

161966488878 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

161966488878 is an abundant number, since it is smaller than the sum of its proper divisors (189145579338).

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

161966488878 is a wasteful number, since it uses less digits than its factorization.

161966488878 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4735280 (or 4735277 counting only the distinct ones).

The product of its digits is 222953472, while the sum is 72.

The spelling of 161966488878 in words is "one hundred sixty-one billion, nine hundred sixty-six million, four hundred eighty-eight thousand, eight hundred seventy-eight".