1309639 has 2 divisors, whose sum is σ = 1309640. Its totient is φ = 1309638.

The previous prime is 1309631. The next prime is 1309661. The reversal of 1309639 is 9369031.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1309639 - 2³ = 1309631 is a prime.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1309639.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1309631) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 654819 + 654820.

It is an arithmetic number, because the mean of its divisors is an integer number (654820).

2^1309639 is an apocalyptic number.

1309639 is a deficient number, since it is larger than the sum of its proper divisors (1).

1309639 is an equidigital number, since it uses as much as digits as its factorization.

1309639 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 4374, while the sum is 31.

The square root of 1309639 is about 1144.3945997775. The cubic root of 1309639 is about 109.4083663099.

The spelling of 1309639 in words is "one million, three hundred nine thousand, six hundred thirty-nine".