18475891813 has 2 divisors, whose sum is σ = 18475891814. Its totient is φ = 18475891812.

The previous prime is 18475891769. The next prime is 18475891817. The reversal of 18475891813 is 31819857481.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 12157708644 + 6318183169 = 110262^2 + 79487^2 .

It is a cyclic number.

It is not a de Polignac number, because 18475891813 - 2²⁹ = 17939020901 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18475891817) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9237945906 + 9237945907.

It is an arithmetic number, because the mean of its divisors is an integer number (9237945907).

Almost surely, 2^18475891813 is an apocalyptic number.

It is an amenable number.

18475891813 is a deficient number, since it is larger than the sum of its proper divisors (1).

18475891813 is an equidigital number, since it uses as much as digits as its factorization.

18475891813 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1935360, while the sum is 55.

The spelling of 18475891813 in words is "eighteen billion, four hundred seventy-five million, eight hundred ninety-one thousand, eight hundred thirteen".