1321421641 has 2 divisors, whose sum is σ = 1321421642. Its totient is φ = 1321421640.

The previous prime is 1321421639. The next prime is 1321421653. The reversal of 1321421641 is 1461241231.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 864360000 + 457061641 = 29400^2 + 21379^2 .

It is a cyclic number.

It is not a de Polignac number, because 1321421641 - 2¹ = 1321421639 is a prime.

Together with 1321421639, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (1321421341) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 660710820 + 660710821.

It is an arithmetic number, because the mean of its divisors is an integer number (660710821).

Almost surely, 2^1321421641 is an apocalyptic number.

It is an amenable number.

1321421641 is a deficient number, since it is larger than the sum of its proper divisors (1).

1321421641 is an equidigital number, since it uses as much as digits as its factorization.

1321421641 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1152, while the sum is 25.

The square root of 1321421641 is about 36351.3636745583. The cubic root of 1321421641 is about 1097.3549785809.

Adding to 1321421641 its reverse (1461241231), we get a palindrome (2782662872).

The spelling of 1321421641 in words is "one billion, three hundred twenty-one million, four hundred twenty-one thousand, six hundred forty-one".