630381821 has 2 divisors, whose sum is σ = 630381822. Its totient is φ = 630381820.

The previous prime is 630381809. The next prime is 630381823. The reversal of 630381821 is 128183036.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 520341721 + 110040100 = 22811^2 + 10490^2 .

It is a cyclic number.

It is not a de Polignac number, because 630381821 - 2¹⁰ = 630380797 is a prime.

Together with 630381823, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (630381823) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 315190910 + 315190911.

It is an arithmetic number, because the mean of its divisors is an integer number (315190911).

Almost surely, 2^630381821 is an apocalyptic number.

It is an amenable number.

630381821 is a deficient number, since it is larger than the sum of its proper divisors (1).

630381821 is an equidigital number, since it uses as much as digits as its factorization.

630381821 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 6912, while the sum is 32.

The square root of 630381821 is about 25107.4057003108. The cubic root of 630381821 is about 857.4350387540.

The spelling of 630381821 in words is "six hundred thirty million, three hundred eighty-one thousand, eight hundred twenty-one".