1266440641 has 2 divisors, whose sum is σ = 1266440642. Its totient is φ = 1266440640.

The previous prime is 1266440627. The next prime is 1266440647. The reversal of 1266440641 is 1460446621.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 981506241 + 284934400 = 31329^2 + 16880^2 .

It is a cyclic number.

It is not a de Polignac number, because 1266440641 - 2¹³ = 1266432449 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1266440597 and 1266440606.

It is not a weakly prime, because it can be changed into another prime (1266440647) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 633220320 + 633220321.

It is an arithmetic number, because the mean of its divisors is an integer number (633220321).

Almost surely, 2^1266440641 is an apocalyptic number.

It is an amenable number.

1266440641 is a deficient number, since it is larger than the sum of its proper divisors (1).

1266440641 is an equidigital number, since it uses as much as digits as its factorization.

1266440641 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 27648, while the sum is 34.

The square root of 1266440641 is about 35587.0853119499. The cubic root of 1266440641 is about 1081.9194948206.

The spelling of 1266440641 in words is "one billion, two hundred sixty-six million, four hundred forty thousand, six hundred forty-one".