1309643 has 4 divisors (see below), whose sum is σ = 1366608. Its totient is φ = 1252680.

The previous prime is 1309639. The next prime is 1309661. The reversal of 1309643 is 3469031.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 1309643 - 2² = 1309639 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1309673) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 28448 + ... + 28493.

It is an arithmetic number, because the mean of its divisors is an integer number (341652).

2^1309643 is an apocalyptic number.

1309643 is a deficient number, since it is larger than the sum of its proper divisors (56965).

1309643 is an equidigital number, since it uses as much as digits as its factorization.

1309643 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 56964.

The product of its (nonzero) digits is 1944, while the sum is 26.

The square root of 1309643 is about 1144.3963474251. The cubic root of 1309643 is about 109.4084776976.

The spelling of 1309643 in words is "one million, three hundred nine thousand, six hundred forty-three".