18408937 has 2 divisors, whose sum is σ = 18408938. Its totient is φ = 18408936.

The previous prime is 18408917. The next prime is 18408941. The reversal of 18408937 is 73980481.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 12362256 + 6046681 = 3516^2 + 2459^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-18408937 is a prime.

It is a super-2 number, since 2×18408937² = 677777922939938, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 18408937.

It is not a weakly prime, because it can be changed into another prime (18408917) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9204468 + 9204469.

It is an arithmetic number, because the mean of its divisors is an integer number (9204469).

Almost surely, 2^18408937 is an apocalyptic number.

It is an amenable number.

18408937 is a deficient number, since it is larger than the sum of its proper divisors (1).

18408937 is an equidigital number, since it uses as much as digits as its factorization.

18408937 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 48384, while the sum is 40.

The square root of 18408937 is about 4290.5637158770. The cubic root of 18408937 is about 264.0439598131.

The spelling of 18408937 in words is "eighteen million, four hundred eight thousand, nine hundred thirty-seven".