631409 has 2 divisors, whose sum is σ = 631410. Its totient is φ = 631408.

The previous prime is 631399. The next prime is 631429. The reversal of 631409 is 904136.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 384400 + 247009 = 620^2 + 497^2 .

It is a cyclic number.

It is not a de Polignac number, because 631409 - 2⁸ = 631153 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (631429) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 315704 + 315705.

It is an arithmetic number, because the mean of its divisors is an integer number (315705).

2⁶³¹⁴⁰⁹ is an apocalyptic number.

It is an amenable number.

631409 is a deficient number, since it is larger than the sum of its proper divisors (1).

631409 is an equidigital number, since it uses as much as digits as its factorization.

631409 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 648, while the sum is 23.

The square root of 631409 is about 794.6124841707. The cubic root of 631409 is about 85.7900503384.

The spelling of 631409 in words is "six hundred thirty-one thousand, four hundred nine".