1631309 has 2 divisors, whose sum is σ = 1631310. Its totient is φ = 1631308.

The previous prime is 1631299. The next prime is 1631341. The reversal of 1631309 is 9031361.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1162084 + 469225 = 1078^2 + 685^2 .

It is an emirp because it is prime and its reverse (9031361) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1631309 - 2⁸ = 1631053 is a prime.

It is a super-2 number, since 2×1631309² = 5322338106962, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1631369) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 815654 + 815655.

It is an arithmetic number, because the mean of its divisors is an integer number (815655).

2^1631309 is an apocalyptic number.

It is an amenable number.

1631309 is a deficient number, since it is larger than the sum of its proper divisors (1).

1631309 is an equidigital number, since it uses as much as digits as its factorization.

1631309 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 486, while the sum is 23.

The square root of 1631309 is about 1277.2270745643. The cubic root of 1631309 is about 117.7186873464.

The spelling of 1631309 in words is "one million, six hundred thirty-one thousand, three hundred nine".