1281645641 has 2 divisors, whose sum is σ = 1281645642. Its totient is φ = 1281645640.

The previous prime is 1281645619. The next prime is 1281645647. The reversal of 1281645641 is 1465461821.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1278420025 + 3225616 = 35755^2 + 1796^2 .

It is an emirp because it is prime and its reverse (1465461821) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1281645641 - 2¹⁴ = 1281629257 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1281645595 and 1281645604.

It is not a weakly prime, because it can be changed into another prime (1281645647) 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, 640822820 + 640822821.

It is an arithmetic number, because the mean of its divisors is an integer number (640822821).

Almost surely, 2^1281645641 is an apocalyptic number.

It is an amenable number.

1281645641 is a deficient number, since it is larger than the sum of its proper divisors (1).

1281645641 is an equidigital number, since it uses as much as digits as its factorization.

1281645641 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 46080, while the sum is 38.

The square root of 1281645641 is about 35800.0787848295. The cubic root of 1281645641 is about 1086.2321553840.

The spelling of 1281645641 in words is "one billion, two hundred eighty-one million, six hundred forty-five thousand, six hundred forty-one".