5538166795561 has 9 divisors (see below), whose sum is σ = 5609345859831. Its totient is φ = 5467879858584.

The previous prime is 5538166795517. The next prime is 5538166795573. The reversal of 5538166795561 is 1655976618355.

The square root of 5538166795561 is 2353331.

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

It can be written as a sum of positive squares in only one way, i.e., 194949623961 + 5343217171600 = 441531^2 + 2311540^2 .

It is a de Polignac number, because none of the positive numbers 2^k-5538166795561 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (5538166795361) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 185898255 + ... + 185928043.

Almost surely, 2^{5538166795561} is an apocalyptic number.

5538166795561 is the 2353331-st square number.

5538166795561 is the 1176666-th centered octagonal number.

It is an amenable number.

5538166795561 is a deficient number, since it is larger than the sum of its proper divisors (71179064270).

5538166795561 is an frugal number, since it uses more digits than its factorization.

5538166795561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 59736 (or 29868 counting only the distinct ones).

The product of its digits is 204120000, while the sum is 67.

The spelling of 5538166795561 in words is "five trillion, five hundred thirty-eight billion, one hundred sixty-six million, seven hundred ninety-five thousand, five hundred sixty-one".