18630973 has 2 divisors, whose sum is σ = 18630974. Its totient is φ = 18630972.

The previous prime is 18630971. The next prime is 18631003. The reversal of 18630973 is 37903681.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 17656804 + 974169 = 4202^2 + 987^2 .

It is an emirp because it is prime and its reverse (37903681) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 18630973 - 2¹ = 18630971 is a prime.

It is a super-2 number, since 2×18630973² = 694226309853458, which contains 22 as substring.

Together with 18630971, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18630971) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9315486 + 9315487.

It is an arithmetic number, because the mean of its divisors is an integer number (9315487).

Almost surely, 2^18630973 is an apocalyptic number.

It is an amenable number.

18630973 is a deficient number, since it is larger than the sum of its proper divisors (1).

18630973 is an equidigital number, since it uses as much as digits as its factorization.

18630973 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 27216, while the sum is 37.

The square root of 18630973 is about 4316.3610831347. The cubic root of 18630973 is about 265.1012927120.

The spelling of 18630973 in words is "eighteen million, six hundred thirty thousand, nine hundred seventy-three".