18930257 has 2 divisors, whose sum is σ = 18930258. Its totient is φ = 18930256.

The previous prime is 18930253. The next prime is 18930269. The reversal of 18930257 is 75203981.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 17673616 + 1256641 = 4204^2 + 1121^2 .

It is a cyclic number.

It is not a de Polignac number, because 18930257 - 2² = 18930253 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (18930253) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9465128 + 9465129.

It is an arithmetic number, because the mean of its divisors is an integer number (9465129).

Almost surely, 2^18930257 is an apocalyptic number.

It is an amenable number.

18930257 is a deficient number, since it is larger than the sum of its proper divisors (1).

18930257 is an equidigital number, since it uses as much as digits as its factorization.

18930257 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 15120, while the sum is 35.

The square root of 18930257 is about 4350.8915178386. The cubic root of 18930257 is about 266.5132692418.

The spelling of 18930257 in words is "eighteen million, nine hundred thirty thousand, two hundred fifty-seven".