161220635144 has 8 divisors (see below), whose sum is σ = 302288690910. Its totient is φ = 80610317568.

The previous prime is 161220635137. The next prime is 161220635167. The reversal of 161220635144 is 441536022161.

It can be written as a sum of positive squares in only one way, i.e., 108853804900 + 52366830244 = 329930^2 + 228838^2 .

It is a tau number, because it is divible by the number of its divisors (8).

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10076289689 + ... + 10076289704.

Almost surely, 2^161220635144 is an apocalyptic number.

It is an amenable number.

161220635144 is a deficient number, since it is larger than the sum of its proper divisors (141068055766).

161220635144 is a wasteful number, since it uses less digits than its factorization.

161220635144 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20152579399 (or 20152579395 counting only the distinct ones).

The product of its (nonzero) digits is 34560, while the sum is 35.

The spelling of 161220635144 in words is "one hundred sixty-one billion, two hundred twenty million, six hundred thirty-five thousand, one hundred forty-four".