1263535649 has 2 divisors, whose sum is σ = 1263535650. Its totient is φ = 1263535648.

The previous prime is 1263535633. The next prime is 1263535673. The reversal of 1263535649 is 9465353621.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 952648225 + 310887424 = 30865^2 + 17632^2 .

It is a cyclic number.

It is not a de Polignac number, because 1263535649 - 2⁴ = 1263535633 is a prime.

It is not a weakly prime, because it can be changed into another prime (1263535619) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 631767824 + 631767825.

It is an arithmetic number, because the mean of its divisors is an integer number (631767825).

Almost surely, 2^1263535649 is an apocalyptic number.

It is an amenable number.

1263535649 is a deficient number, since it is larger than the sum of its proper divisors (1).

1263535649 is an equidigital number, since it uses as much as digits as its factorization.

1263535649 is an evil number, because the sum of its binary digits is even.

The product of its digits is 583200, while the sum is 44.

The square root of 1263535649 is about 35546.2466232372. The cubic root of 1263535649 is about 1081.0916171766.

It can be divided in two parts, 12635 and 35649, that added together give a palindrome (48284).

The spelling of 1263535649 in words is "one billion, two hundred sixty-three million, five hundred thirty-five thousand, six hundred forty-nine".