1263821957 has 2 divisors, whose sum is σ = 1263821958. Its totient is φ = 1263821956.

The previous prime is 1263821921. The next prime is 1263821969. The reversal of 1263821957 is 7591283621.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 726787681 + 537034276 = 26959^2 + 23174^2 .

It is a cyclic number.

It is not a de Polignac number, because 1263821957 - 2⁶ = 1263821893 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1263826957) 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, 631910978 + 631910979.

It is an arithmetic number, because the mean of its divisors is an integer number (631910979).

Almost surely, 2^1263821957 is an apocalyptic number.

It is an amenable number.

1263821957 is a deficient number, since it is larger than the sum of its proper divisors (1).

1263821957 is an equidigital number, since it uses as much as digits as its factorization.

1263821957 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 181440, while the sum is 44.

The square root of 1263821957 is about 35550.2736557681. The cubic root of 1263821957 is about 1081.1732668457.

The spelling of 1263821957 in words is "one billion, two hundred sixty-three million, eight hundred twenty-one thousand, nine hundred fifty-seven".