161889360780625 has 15 divisors (see below), whose sum is σ = 202297342716733. Its totient is φ = 129511234153000.

The previous prime is 161889360780551. The next prime is 161889360780671. The reversal of 161889360780625 is 526087063988161.

The square root of 161889360780625 is 12723575.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in 2 ways, for example, as 12692125885201 + 149197234895424 = 3562601^2 + 12214632^2 .

It is not a de Polignac number, because 161889360780625 - 2²³ = 161889352392017 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 14 ways as a sum of consecutive naturals, for example, 317834904 + ... + 318343846.

Almost surely, 2^{161889360780625} is an apocalyptic number.

161889360780625 is the 12723575-th square number.

161889360780625 is the 6361788-th centered octagonal number.

It is an amenable number.

161889360780625 is a deficient number, since it is larger than the sum of its proper divisors (40407981936108).

161889360780625 is an frugal number, since it uses more digits than its factorization.

161889360780625 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1017906 (or 508948 counting only the distinct ones).

The product of its (nonzero) digits is 209018880, while the sum is 70.

The spelling of 161889360780625 in words is "one hundred sixty-one trillion, eight hundred eighty-nine billion, three hundred sixty million, seven hundred eighty thousand, six hundred twenty-five".