18501499449 has 24 divisors (see below), whose sum is σ = 28452787272. Its totient is φ = 11544629760.

The previous prime is 18501499439. The next prime is 18501499469. The reversal of 18501499449 is 94499410581.

18501499449 is a `hidden beast` number, since 1 + 8 + 50 + 149 + 9 + 449 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 59049 + 18501440400 = 243^2 + 136020^2 .

It is not a de Polignac number, because 18501499449 - 2¹⁶ = 18501433913 is a prime.

It is a super-2 number, since 2×18501499449² (a number of 21 digits) contains 22 as substring.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 18501499395 and 18501499404.

It is not an unprimeable number, because it can be changed into a prime (18501499439) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 306354 + ... + 361739.

It is an arithmetic number, because the mean of its divisors is an integer number (1185532803).

Almost surely, 2^18501499449 is an apocalyptic number.

It is an amenable number.

18501499449 is a deficient number, since it is larger than the sum of its proper divisors (9951287823).

18501499449 is a wasteful number, since it uses less digits than its factorization.

18501499449 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 668297 (or 668294 counting only the distinct ones).

The product of its (nonzero) digits is 1866240, while the sum is 54.

The spelling of 18501499449 in words is "eighteen billion, five hundred one million, four hundred ninety-nine thousand, four hundred forty-nine".