631247989 has 2 divisors, whose sum is σ = 631247990. Its totient is φ = 631247988.

The previous prime is 631247873. The next prime is 631247993. The reversal of 631247989 is 989742136.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 550840900 + 80407089 = 23470^2 + 8967^2 .

It is a cyclic number.

It is not a de Polignac number, because 631247989 - 2¹⁹ = 630723701 is a prime.

It is equal to p_32868769 and since 631247989 and 32868769 have the same sum of digits, it is a Honaker prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (631257989) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 315623994 + 315623995.

It is an arithmetic number, because the mean of its divisors is an integer number (315623995).

Almost surely, 2^631247989 is an apocalyptic number.

It is an amenable number.

631247989 is a deficient number, since it is larger than the sum of its proper divisors (1).

631247989 is an equidigital number, since it uses as much as digits as its factorization.

631247989 is an evil number, because the sum of its binary digits is even.

The product of its digits is 653184, while the sum is 49.

The square root of 631247989 is about 25124.6490323746. The cubic root of 631247989 is about 857.8275748696.

It can be divided in two parts, 631247 and 989, that added together give a palindrome (632236).

The spelling of 631247989 in words is "six hundred thirty-one million, two hundred forty-seven thousand, nine hundred eighty-nine".