1243025681 has 2 divisors, whose sum is σ = 1243025682. Its totient is φ = 1243025680.

The previous prime is 1243025633. The next prime is 1243025713. The reversal of 1243025681 is 1865203421.

It is an a-pointer prime, because the next prime (1243025713) can be obtained adding 1243025681 to its sum of digits (32).

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 908721025 + 334304656 = 30145^2 + 18284^2 .

It is a cyclic number.

It is not a de Polignac number, because 1243025681 - 2⁶ = 1243025617 is a prime.

It is a super-2 number, since 2×1243025681² = 3090225687251027522, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (1243025611) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 621512840 + 621512841.

It is an arithmetic number, because the mean of its divisors is an integer number (621512841).

Almost surely, 2^1243025681 is an apocalyptic number.

It is an amenable number.

1243025681 is a deficient number, since it is larger than the sum of its proper divisors (1).

1243025681 is an equidigital number, since it uses as much as digits as its factorization.

1243025681 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 11520, while the sum is 32.

The square root of 1243025681 is about 35256.5693311190. The cubic root of 1243025681 is about 1075.2101787708.

The spelling of 1243025681 in words is "one billion, two hundred forty-three million, twenty-five thousand, six hundred eighty-one".