161521577704 has 16 divisors (see below), whose sum is σ = 313296164100. Its totient is φ = 77975933952.

The previous prime is 161521577699. The next prime is 161521577713. The reversal of 161521577704 is 407775125161.

It can be written as a sum of positive squares in 2 ways, for example, as 159816052900 + 1705524804 = 399770^2 + 41298^2 .

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 3 ways as a sum of consecutive naturals, for example, 348106617 + ... + 348107080.

Almost surely, 2^161521577704 is an apocalyptic number.

It is an amenable number.

161521577704 is a deficient number, since it is larger than the sum of its proper divisors (151774586396).

161521577704 is a wasteful number, since it uses less digits than its factorization.

161521577704 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 696213732 (or 696213728 counting only the distinct ones).

The product of its (nonzero) digits is 411600, while the sum is 46.

The spelling of 161521577704 in words is "one hundred sixty-one billion, five hundred twenty-one million, five hundred seventy-seven thousand, seven hundred four".