18729749 has 2 divisors, whose sum is σ = 18729750. Its totient is φ = 18729748.

The previous prime is 18729731. The next prime is 18729757. The reversal of 18729749 is 94792781.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 13823524 + 4906225 = 3718^2 + 2215^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-18729749 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18729709) 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, 9364874 + 9364875.

It is an arithmetic number, because the mean of its divisors is an integer number (9364875).

Almost surely, 2^18729749 is an apocalyptic number.

It is an amenable number.

18729749 is a deficient number, since it is larger than the sum of its proper divisors (1).

18729749 is an equidigital number, since it uses as much as digits as its factorization.

18729749 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 254016, while the sum is 47.

The square root of 18729749 is about 4327.7880031258. The cubic root of 18729749 is about 265.5689638473.

The spelling of 18729749 in words is "eighteen million, seven hundred twenty-nine thousand, seven hundred forty-nine".