631541809 has 2 divisors, whose sum is σ = 631541810. Its totient is φ = 631541808.

The previous prime is 631541753. The next prime is 631541831. The reversal of 631541809 is 908145136.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 374035600 + 257506209 = 19340^2 + 16047^2 .

It is a cyclic number.

It is not a de Polignac number, because 631541809 - 2¹¹ = 631539761 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (631541839) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 315770904 + 315770905.

It is an arithmetic number, because the mean of its divisors is an integer number (315770905).

Almost surely, 2^631541809 is an apocalyptic number.

It is an amenable number.

631541809 is a deficient number, since it is larger than the sum of its proper divisors (1).

631541809 is an equidigital number, since it uses as much as digits as its factorization.

631541809 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 25920, while the sum is 37.

The square root of 631541809 is about 25130.4955979782. The cubic root of 631541809 is about 857.9606487206.

The spelling of 631541809 in words is "six hundred thirty-one million, five hundred forty-one thousand, eight hundred nine".