493988021 has 2 divisors, whose sum is σ = 493988022. Its totient is φ = 493988020.

The previous prime is 493988017. The next prime is 493988081. The reversal of 493988021 is 120889394.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 493284100 + 703921 = 22210^2 + 839^2 .

It is a cyclic number.

It is not a de Polignac number, because 493988021 - 2² = 493988017 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (493988081) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 246994010 + 246994011.

It is an arithmetic number, because the mean of its divisors is an integer number (246994011).

Almost surely, 2^493988021 is an apocalyptic number.

It is an amenable number.

493988021 is a deficient number, since it is larger than the sum of its proper divisors (1).

493988021 is an equidigital number, since it uses as much as digits as its factorization.

493988021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 124416, while the sum is 44.

The square root of 493988021 is about 22225.8412889141. The cubic root of 493988021 is about 790.5065495625.

The spelling of 493988021 in words is "four hundred ninety-three million, nine hundred eighty-eight thousand, twenty-one".