18356278049 has 4 divisors (see below), whose sum is σ = 18356551236. Its totient is φ = 18356004864.

The previous prime is 18356278007. The next prime is 18356278079. The reversal of 18356278049 is 94087265381.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 11933377600 + 6422900449 = 109240^2 + 80143^2 .

It is a cyclic number.

It is not a de Polignac number, because 18356278049 - 2²⁸ = 18087842593 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18356278079) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 42257 + ... + 196209.

It is an arithmetic number, because the mean of its divisors is an integer number (4589137809).

It is a 1-persistent number, because it is pandigital, but 2⋅18356278049 = 36712556098 is not.

Almost surely, 2^18356278049 is an apocalyptic number.

It is an amenable number.

18356278049 is a deficient number, since it is larger than the sum of its proper divisors (273187).

18356278049 is a wasteful number, since it uses less digits than its factorization.

18356278049 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 273186.

The product of its (nonzero) digits is 2903040, while the sum is 53.

The spelling of 18356278049 in words is "eighteen billion, three hundred fifty-six million, two hundred seventy-eight thousand, forty-nine".