1263981281 has 2 divisors, whose sum is σ = 1263981282. Its totient is φ = 1263981280.

The previous prime is 1263981253. The next prime is 1263981283. The reversal of 1263981281 is 1821893621.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 929274256 + 334707025 = 30484^2 + 18295^2 .

It is a cyclic number.

It is not a de Polignac number, because 1263981281 - 2¹⁰ = 1263980257 is a prime.

It is a super-2 number, since 2×1263981281² = 3195297357436801922, which contains 22 as substring.

Together with 1263981283, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (1263981283) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 631990640 + 631990641.

It is an arithmetic number, because the mean of its divisors is an integer number (631990641).

Almost surely, 2^1263981281 is an apocalyptic number.

It is an amenable number.

1263981281 is a deficient number, since it is larger than the sum of its proper divisors (1).

1263981281 is an equidigital number, since it uses as much as digits as its factorization.

1263981281 is an evil number, because the sum of its binary digits is even.

The product of its digits is 41472, while the sum is 41.

The square root of 1263981281 is about 35552.5144117825. The cubic root of 1263981281 is about 1081.2186977206.

The spelling of 1263981281 in words is "one billion, two hundred sixty-three million, nine hundred eighty-one thousand, two hundred eighty-one".