631863109 has 2 divisors, whose sum is σ = 631863110. Its totient is φ = 631863108.

The previous prime is 631863101. The next prime is 631863121. The reversal of 631863109 is 901368136.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 631114884 + 748225 = 25122^2 + 865^2 .

It is a cyclic number.

It is not a de Polignac number, because 631863109 - 2³ = 631863101 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (631863101) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 315931554 + 315931555.

It is an arithmetic number, because the mean of its divisors is an integer number (315931555).

Almost surely, 2^631863109 is an apocalyptic number.

It is an amenable number.

631863109 is a deficient number, since it is larger than the sum of its proper divisors (1).

631863109 is an equidigital number, since it uses as much as digits as its factorization.

631863109 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 23328, while the sum is 37.

The square root of 631863109 is about 25136.8874167030. The cubic root of 631863109 is about 858.1061212860.

The spelling of 631863109 in words is "six hundred thirty-one million, eight hundred sixty-three thousand, one hundred nine".