18549294581 has 4 divisors (see below), whose sum is σ = 18826149792. Its totient is φ = 18272439372.

The previous prime is 18549294493. The next prime is 18549294611.

18549294581 is nontrivially palindromic in base 10.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 18549294581 - 2¹⁴ = 18549278197 is a prime.

It is a super-2 number, since 2×18549294581² (a number of 21 digits) contains 22 as substring.

It is an alternating number because its digits alternate between odd and even.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18549290581) 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, 138427505 + ... + 138427638.

It is an arithmetic number, because the mean of its divisors is an integer number (4706537448).

Almost surely, 2^18549294581 is an apocalyptic number.

It is an amenable number.

18549294581 is a deficient number, since it is larger than the sum of its proper divisors (276855211).

18549294581 is an equidigital number, since it uses as much as digits as its factorization.

18549294581 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 276855210.

The product of its digits is 4147200, while the sum is 56.

The spelling of 18549294581 in words is "eighteen billion, five hundred forty-nine million, two hundred ninety-four thousand, five hundred eighty-one".