631387 has 2 divisors, whose sum is σ = 631388. Its totient is φ = 631386.

The previous prime is 631361. The next prime is 631391. The reversal of 631387 is 783136.

631387 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 631387 - 2⁷ = 631259 is a prime.

It is not a weakly prime, because it can be changed into another prime (631307) by changing a digit.

It is a good prime.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 315693 + 315694.

It is an arithmetic number, because the mean of its divisors is an integer number (315694).

2⁶³¹³⁸⁷ is an apocalyptic number.

631387 is a deficient number, since it is larger than the sum of its proper divisors (1).

631387 is an equidigital number, since it uses as much as digits as its factorization.

631387 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3024, while the sum is 28.

The square root of 631387 is about 794.5986408244. The cubic root of 631387 is about 85.7890539409.

It can be divided in two parts, 6313 and 87, that added together give a square (6400 = 80²).

The spelling of 631387 in words is "six hundred thirty-one thousand, three hundred eighty-seven".