18237493 has 2 divisors, whose sum is σ = 18237494. Its totient is φ = 18237492.

The previous prime is 18237463. The next prime is 18237509. The reversal of 18237493 is 39473281.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 18130564 + 106929 = 4258^2 + 327^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-18237493 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18237463) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9118746 + 9118747.

It is an arithmetic number, because the mean of its divisors is an integer number (9118747).

Almost surely, 2^18237493 is an apocalyptic number.

It is an amenable number.

18237493 is a deficient number, since it is larger than the sum of its proper divisors (1).

18237493 is an equidigital number, since it uses as much as digits as its factorization.

18237493 is an evil number, because the sum of its binary digits is even.

The product of its digits is 36288, while the sum is 37.

The square root of 18237493 is about 4270.5377881480. The cubic root of 18237493 is about 263.2217139863.

It can be divided in two parts, 1823 and 7493, that added together give a triangular number (9316 = T₁₃₆).

The spelling of 18237493 in words is "eighteen million, two hundred thirty-seven thousand, four hundred ninety-three".