1265126389 has 2 divisors, whose sum is σ = 1265126390. Its totient is φ = 1265126388.

The previous prime is 1265126371. The next prime is 1265126413. The reversal of 1265126389 is 9836215621.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1250188164 + 14938225 = 35358^2 + 3865^2 .

It is a cyclic number.

It is not a de Polignac number, because 1265126389 - 2¹⁷ = 1264995317 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1265126309) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 632563194 + 632563195.

It is an arithmetic number, because the mean of its divisors is an integer number (632563195).

Almost surely, 2^1265126389 is an apocalyptic number.

It is an amenable number.

1265126389 is a deficient number, since it is larger than the sum of its proper divisors (1).

1265126389 is an equidigital number, since it uses as much as digits as its factorization.

1265126389 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 155520, while the sum is 43.

The square root of 1265126389 is about 35568.6152246612. The cubic root of 1265126389 is about 1081.5451103810.

The spelling of 1265126389 in words is "one billion, two hundred sixty-five million, one hundred twenty-six thousand, three hundred eighty-nine".