18779021 has 2 divisors, whose sum is σ = 18779022. Its totient is φ = 18779020.

The previous prime is 18779009. The next prime is 18779041. The reversal of 18779021 is 12097781.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 18232900 + 546121 = 4270^2 + 739^2 .

It is a cyclic number.

It is not a de Polignac number, because 18779021 - 2⁶ = 18778957 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 (18779041) 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, 9389510 + 9389511.

It is an arithmetic number, because the mean of its divisors is an integer number (9389511).

Almost surely, 2^18779021 is an apocalyptic number.

It is an amenable number.

18779021 is a deficient number, since it is larger than the sum of its proper divisors (1).

18779021 is an equidigital number, since it uses as much as digits as its factorization.

18779021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 7056, while the sum is 35.

The square root of 18779021 is about 4333.4767796770. The cubic root of 18779021 is about 265.8016357048.

The spelling of 18779021 in words is "eighteen million, seven hundred seventy-nine thousand, twenty-one".