18937973 has 2 divisors, whose sum is σ = 18937974. Its totient is φ = 18937972.

The previous prime is 18937951. The next prime is 18937979. The reversal of 18937973 is 37973981.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 10510564 + 8427409 = 3242^2 + 2903^2 .

It is a cyclic number.

It is not a de Polignac number, because 18937973 - 2¹⁶ = 18872437 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18937979) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9468986 + 9468987.

It is an arithmetic number, because the mean of its divisors is an integer number (9468987).

Almost surely, 2^18937973 is an apocalyptic number.

It is an amenable number.

18937973 is a deficient number, since it is larger than the sum of its proper divisors (1).

18937973 is an equidigital number, since it uses as much as digits as its factorization.

18937973 is an evil number, because the sum of its binary digits is even.

The product of its digits is 285768, while the sum is 47.

The square root of 18937973 is about 4351.7781423230. The cubic root of 18937973 is about 266.5494747205.

The spelling of 18937973 in words is "eighteen million, nine hundred thirty-seven thousand, nine hundred seventy-three".