1431221221 has 2 divisors, whose sum is σ = 1431221222. Its totient is φ = 1431221220.

The previous prime is 1431221219. The next prime is 1431221251. The reversal of 1431221221 is 1221221341.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 771450625 + 659770596 = 27775^2 + 25686^2 .

It is an emirp because it is prime and its reverse (1221221341) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1431221221 - 2¹ = 1431221219 is a prime.

Together with 1431221219, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1431221251) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 715610610 + 715610611.

It is an arithmetic number, because the mean of its divisors is an integer number (715610611).

Almost surely, 2^1431221221 is an apocalyptic number.

It is an amenable number.

1431221221 is a deficient number, since it is larger than the sum of its proper divisors (1).

1431221221 is an equidigital number, since it uses as much as digits as its factorization.

1431221221 is an evil number, because the sum of its binary digits is even.

The product of its digits is 192, while the sum is 19.

The square root of 1431221221 is about 37831.4845201718. The cubic root of 1431221221 is about 1126.9437924071.

Adding to 1431221221 its reverse (1221221341), we get a palindrome (2652442562).

The spelling of 1431221221 in words is "one billion, four hundred thirty-one million, two hundred twenty-one thousand, two hundred twenty-one".