1221245231 has 2 divisors, whose sum is σ = 1221245232. Its totient is φ = 1221245230.

The previous prime is 1221245209. The next prime is 1221245287. The reversal of 1221245231 is 1325421221.

It is a weak prime.

It is an emirp because it is prime and its reverse (1325421221) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1221245231 - 2¹⁰ = 1221244207 is a prime.

It is a super-2 number, since 2×1221245231² = 2982879828480486722, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 1221245197 and 1221245206.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1221245731) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 610622615 + 610622616.

It is an arithmetic number, because the mean of its divisors is an integer number (610622616).

Almost surely, 2^1221245231 is an apocalyptic number.

1221245231 is a deficient number, since it is larger than the sum of its proper divisors (1).

1221245231 is an equidigital number, since it uses as much as digits as its factorization.

1221245231 is an evil number, because the sum of its binary digits is even.

The product of its digits is 960, while the sum is 23.

The square root of 1221245231 is about 34946.3192768566. The cubic root of 1221245231 is about 1068.8931492489.

Adding to 1221245231 its reverse (1325421221), we get a palindrome (2546666452).

The spelling of 1221245231 in words is "one billion, two hundred twenty-one million, two hundred forty-five thousand, two hundred thirty-one".