161878881612 has 144 divisors (see below), whose sum is σ = 454572582912. Its totient is φ = 43915618560.

The previous prime is 161878881607. The next prime is 161878881649. The reversal of 161878881612 is 216188878161.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 6074437 + ... + 6101027.

It is an arithmetic number, because the mean of its divisors is an integer number (3156754048).

Almost surely, 2^161878881612 is an apocalyptic number.

161878881612 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 161878881612, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (227286291456).

161878881612 is an abundant number, since it is smaller than the sum of its proper divisors (292693701300).

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

161878881612 is a wasteful number, since it uses less digits than its factorization.

161878881612 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26788 (or 26763 counting only the distinct ones).

The product of its digits is 2064384, while the sum is 57.

The spelling of 161878881612 in words is "one hundred sixty-one billion, eight hundred seventy-eight million, eight hundred eighty-one thousand, six hundred twelve".