1808134719561 has 81 divisors (see below), whose sum is σ = 2720133287053. Its totient is φ = 1157383501680.

The previous prime is 1808134719551. The next prime is 1808134719577. The reversal of 1808134719561 is 1659174318081.

The square root of 1808134719561 is 1344669.

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

1808134719561 is a `hidden beast` number, since 1 + 8 + 0 + 8 + 1 + 3 + 4 + 71 + 9 + 561 = 666.

It is not a de Polignac number, because 1808134719561 - 2¹⁷ = 1808134588489 is a prime.

It is a super-2 number, since 2×1808134719561² (a number of 25 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1808134719498 and 1808134719507.

It is not an unprimeable number, because it can be changed into a prime (1808134719551) by changing a digit.

It is a polite number, since it can be written in 80 ways as a sum of consecutive naturals, for example, 16898455270 + ... + 16898455376.

Almost surely, 2^{1808134719561} is an apocalyptic number.

1808134719561 is the 1344669-th square number.

1808134719561 is the 672335-th centered octagonal number.

It is an amenable number.

1808134719561 is a deficient number, since it is larger than the sum of its proper divisors (911998567492).

1808134719561 is an frugal number, since it uses more digits than its factorization.

1808134719561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 480 (or 240 counting only the distinct ones).

The product of its (nonzero) digits is 1451520, while the sum is 54.

The spelling of 1808134719561 in words is "one trillion, eight hundred eight billion, one hundred thirty-four million, seven hundred nineteen thousand, five hundred sixty-one".