1321738645 has 8 divisors (see below), whose sum is σ = 1616012856. Its totient is φ = 1037439936.

The previous prime is 1321738643. The next prime is 1321738669. The reversal of 1321738645 is 5468371231.

It can be written as a sum of positive squares in 4 ways, for example, as 40170244 + 1281568401 = 6338^2 + 35799^2 .

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 1321738645 - 2¹ = 1321738643 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1321738598 and 1321738607.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1321738643) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2493582 + ... + 2494111.

It is an arithmetic number, because the mean of its divisors is an integer number (202001607).

Almost surely, 2^1321738645 is an apocalyptic number.

It is an amenable number.

1321738645 is a deficient number, since it is larger than the sum of its proper divisors (294274211).

1321738645 is an equidigital number, since it uses as much as digits as its factorization.

1321738645 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4987751.

The product of its digits is 120960, while the sum is 40.

The square root of 1321738645 is about 36355.7236896751. The cubic root of 1321738645 is about 1097.4427219862.

The spelling of 1321738645 in words is "one billion, three hundred twenty-one million, seven hundred thirty-eight thousand, six hundred forty-five".