4161759121521 has 21 divisors (see below), whose sum is σ = 6239866837051. Its totient is φ = 2774469360312.

The previous prime is 4161759121489. The next prime is 4161759121589. The reversal of 4161759121521 is 1251219571614.

The square root of 4161759121521 is 2040039.

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

4161759121521 is a `hidden beast` number, since 4 + 1 + 6 + 1 + 7 + 591 + 2 + 1 + 52 + 1 = 666.

It can be written as a sum of positive squares in only one way, i.e., 3708609350625 + 453149770896 = 1925775^2 + 673164^2 .

It is not a de Polignac number, because 4161759121521 - 2⁵ = 4161759121489 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (4161759121591) by changing a digit.

It is a polite number, since it can be written in 20 ways as a sum of consecutive naturals, for example, 55043275 + ... + 55118831.

Almost surely, 2^{4161759121521} is an apocalyptic number.

4161759121521 is the 2040039-th square number.

4161759121521 is the 1020020-th centered octagonal number.

It is an amenable number.

4161759121521 is a deficient number, since it is larger than the sum of its proper divisors (2078107715530).

4161759121521 is an frugal number, since it uses more digits than its factorization.

4161759121521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 151132 (or 75560 counting only the distinct ones).

The product of its digits is 151200, while the sum is 45.

The spelling of 4161759121521 in words is "four trillion, one hundred sixty-one billion, seven hundred fifty-nine million, one hundred twenty-one thousand, five hundred twenty-one".