18500051 has 2 divisors, whose sum is σ = 18500052. Its totient is φ = 18500050.

The previous prime is 18500047. The next prime is 18500071. The reversal of 18500051 is 15000581.

It is an a-pointer prime, because the next prime (18500071) can be obtained adding 18500051 to its sum of digits (20).

It is a weak prime.

It is an emirp because it is prime and its reverse (15000581) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 18500051 - 2² = 18500047 is a prime.

It is equal to p_1181162 and since 18500051 and 1181162 have the same sum of digits, it is a Honaker prime.

It is a junction number, because it is equal to n+sod(n) for n = 18499996 and 18500032.

It is not a weakly prime, because it can be changed into another prime (18500071) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9250025 + 9250026.

It is an arithmetic number, because the mean of its divisors is an integer number (9250026).

Almost surely, 2^18500051 is an apocalyptic number.

18500051 is a deficient number, since it is larger than the sum of its proper divisors (1).

18500051 is an equidigital number, since it uses as much as digits as its factorization.

18500051 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 200, while the sum is 20.

The square root of 18500051 is about 4301.1685621468. The cubic root of 18500051 is about 264.4788666689.

The spelling of 18500051 in words is "eighteen million, five hundred thousand, fifty-one".