18540013 has 4 divisors (see below), whose sum is σ = 19630620. Its totient is φ = 17449408.

The previous prime is 18540007. The next prime is 18540031. The reversal of 18540013 is 31004581.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 31004581 = 877 ⋅35353.

It can be written as a sum of positive squares in 2 ways, for example, as 6135529 + 12404484 = 2477^2 + 3522^2 .

It is a cyclic number.

It is not a de Polignac number, because 18540013 - 2¹⁷ = 18408941 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18540083) 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, 545278 + ... + 545311.

It is an arithmetic number, because the mean of its divisors is an integer number (4907655).

Almost surely, 2^18540013 is an apocalyptic number.

It is an amenable number.

18540013 is a deficient number, since it is larger than the sum of its proper divisors (1090607).

18540013 is a wasteful number, since it uses less digits than its factorization.

18540013 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1090606.

The product of its (nonzero) digits is 480, while the sum is 22.

The square root of 18540013 is about 4305.8115379101. The cubic root of 18540013 is about 264.6691635042.

Adding to 18540013 its reverse (31004581), we get a palindrome (49544594).

The spelling of 18540013 in words is "eighteen million, five hundred forty thousand, thirteen".