161938009571 has 8 divisors (see below), whose sum is σ = 175565216400. Its totient is φ = 148478008032.

The previous prime is 161938009567. The next prime is 161938009577. The reversal of 161938009571 is 175900839161.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 161938009571 - 2² = 161938009567 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (161938009577) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 41799305 + ... + 41803178.

It is an arithmetic number, because the mean of its divisors is an integer number (21945652050).

Almost surely, 2^161938009571 is an apocalyptic number.

161938009571 is a deficient number, since it is larger than the sum of its proper divisors (13627206829).

161938009571 is a wasteful number, since it uses less digits than its factorization.

161938009571 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 83602645.

The product of its (nonzero) digits is 408240, while the sum is 50.

The spelling of 161938009571 in words is "one hundred sixty-one billion, nine hundred thirty-eight million, nine thousand, five hundred seventy-one".