1309256641 has 8 divisors (see below), whose sum is σ = 1632320064. Its totient is φ = 1020199920.

The previous prime is 1309256549. The next prime is 1309256671. The reversal of 1309256641 is 1466529031.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1309256641 - 2²¹ = 1307159489 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1309256641.

It is not an unprimeable number, because it can be changed into a prime (1309256671) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 8501590 + ... + 8501743.

It is an arithmetic number, because the mean of its divisors is an integer number (204040008).

Almost surely, 2^1309256641 is an apocalyptic number.

1309256641 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1309256641 is a deficient number, since it is larger than the sum of its proper divisors (323063423).

1309256641 is a wasteful number, since it uses less digits than its factorization.

1309256641 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17003351.

The product of its (nonzero) digits is 38880, while the sum is 37.

The square root of 1309256641 is about 36183.6515708407. The cubic root of 1309256641 is about 1093.9771774051.

The spelling of 1309256641 in words is "one billion, three hundred nine million, two hundred fifty-six thousand, six hundred forty-one".