631380509 has 2 divisors, whose sum is σ = 631380510. Its totient is φ = 631380508.

The previous prime is 631380473. The next prime is 631380511. The reversal of 631380509 is 905083136.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 595116025 + 36264484 = 24395^2 + 6022^2 .

It is a cyclic number.

It is not a de Polignac number, because 631380509 - 2¹⁶ = 631314973 is a prime.

Together with 631380511, 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 (631380809) 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, 315690254 + 315690255.

It is an arithmetic number, because the mean of its divisors is an integer number (315690255).

Almost surely, 2^631380509 is an apocalyptic number.

It is an amenable number.

631380509 is a deficient number, since it is larger than the sum of its proper divisors (1).

631380509 is an equidigital number, since it uses as much as digits as its factorization.

631380509 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 19440, while the sum is 35.

The square root of 631380509 is about 25127.2861447471. The cubic root of 631380509 is about 857.8875995393.

The spelling of 631380509 in words is "six hundred thirty-one million, three hundred eighty thousand, five hundred nine".