18478513 has 2 divisors, whose sum is σ = 18478514. Its totient is φ = 18478512.

The previous prime is 18478501. The next prime is 18478517. The reversal of 18478513 is 31587481.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 15944049 + 2534464 = 3993^2 + 1592^2 .

It is a cyclic number.

It is not a de Polignac number, because 18478513 - 2¹³ = 18470321 is a prime.

It is a super-4 number, since 4×18478513⁴ (a number of 30 digits) contains 4444 as substring.

It is not a weakly prime, because it can be changed into another prime (18478517) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9239256 + 9239257.

It is an arithmetic number, because the mean of its divisors is an integer number (9239257).

Almost surely, 2^18478513 is an apocalyptic number.

It is an amenable number.

18478513 is a deficient number, since it is larger than the sum of its proper divisors (1).

18478513 is an equidigital number, since it uses as much as digits as its factorization.

18478513 is an evil number, because the sum of its binary digits is even.

The product of its digits is 26880, while the sum is 37.

The square root of 18478513 is about 4298.6640948090. The cubic root of 18478513 is about 264.3761902340.

The spelling of 18478513 in words is "eighteen million, four hundred seventy-eight thousand, five hundred thirteen".