18128737449 has 27 divisors (see below), whose sum is σ = 26935015653. Its totient is φ = 11749486752.

The previous prime is 18128737447. The next prime is 18128737519. The reversal of 18128737449 is 94473782181.

The square root of 18128737449 is 134643.

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

18128737449 is a `hidden beast` number, since 1 + 8 + 128 + 73 + 7 + 449 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 290463849 + 17838273600 = 17043^2 + 133560^2 .

It is not a de Polignac number, because 18128737449 - 2¹ = 18128737447 is a prime.

It is a super-2 number, since 2×18128737449² (a number of 21 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 18128737395 and 18128737404.

It is not an unprimeable number, because it can be changed into a prime (18128737447) by changing a digit.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 14944767 + ... + 14945979.

Almost surely, 2^18128737449 is an apocalyptic number.

18128737449 is the 134643-rd square number.

18128737449 is the 67322-nd centered octagonal number.

It is an amenable number.

18128737449 is a deficient number, since it is larger than the sum of its proper divisors (8806278204).

18128737449 is an frugal number, since it uses more digits than its factorization.

18128737449 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2506 (or 1253 counting only the distinct ones).

The product of its digits is 2709504, while the sum is 54.

The spelling of 18128737449 in words is "eighteen billion, one hundred twenty-eight million, seven hundred thirty-seven thousand, four hundred forty-nine".