1243623281 has 2 divisors, whose sum is σ = 1243623282. Its totient is φ = 1243623280.

The previous prime is 1243623233. The next prime is 1243623289. The reversal of 1243623281 is 1823263421.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 853165681 + 390457600 = 29209^2 + 19760^2 .

It is a cyclic number.

It is not a de Polignac number, because 1243623281 - 2¹⁸ = 1243361137 is a prime.

It is a super-2 number, since 2×1243623281² = 3093197730090409922, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (1243623289) 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 as a sum of consecutive naturals, namely, 621811640 + 621811641.

It is an arithmetic number, because the mean of its divisors is an integer number (621811641).

Almost surely, 2^1243623281 is an apocalyptic number.

It is an amenable number.

1243623281 is a deficient number, since it is larger than the sum of its proper divisors (1).

1243623281 is an equidigital number, since it uses as much as digits as its factorization.

1243623281 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 13824, while the sum is 32.

The square root of 1243623281 is about 35265.0433290532. The cubic root of 1243623281 is about 1075.3824580378.

The spelling of 1243623281 in words is "one billion, two hundred forty-three million, six hundred twenty-three thousand, two hundred eighty-one".