18773641 has 2 divisors, whose sum is σ = 18773642. Its totient is φ = 18773640.

The previous prime is 18773609. The next prime is 18773647. The reversal of 18773641 is 14637781.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 15968016 + 2805625 = 3996^2 + 1675^2 .

It is an emirp because it is prime and its reverse (14637781) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 18773641 - 2⁵ = 18773609 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 18773641.

It is not a weakly prime, because it can be changed into another prime (18773647) 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, 9386820 + 9386821.

It is an arithmetic number, because the mean of its divisors is an integer number (9386821).

Almost surely, 2^18773641 is an apocalyptic number.

It is an amenable number.

18773641 is a deficient number, since it is larger than the sum of its proper divisors (1).

18773641 is an equidigital number, since it uses as much as digits as its factorization.

18773641 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 28224, while the sum is 37.

The square root of 18773641 is about 4332.8559865290. The cubic root of 18773641 is about 265.7762501184.

The spelling of 18773641 in words is "eighteen million, seven hundred seventy-three thousand, six hundred forty-one".