161868321644 has 48 divisors (see below), whose sum is σ = 287137686528. Its totient is φ = 79838820288.

The previous prime is 161868321617. The next prime is 161868321683. The reversal of 161868321644 is 446123868161.

It is a junction number, because it is equal to n+sod(n) for n = 161868321592 and 161868321601.

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 15 ways as a sum of consecutive naturals, for example, 51109349 + ... + 51112515.

It is an arithmetic number, because the mean of its divisors is an integer number (5982035136).

Almost surely, 2^161868321644 is an apocalyptic number.

It is an amenable number.

161868321644 is a deficient number, since it is larger than the sum of its proper divisors (125269364884).

161868321644 is a wasteful number, since it uses less digits than its factorization.

161868321644 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3894 (or 3892 counting only the distinct ones).

The product of its digits is 1327104, while the sum is 50.

The spelling of 161868321644 in words is "one hundred sixty-one billion, eight hundred sixty-eight million, three hundred twenty-one thousand, six hundred forty-four".