1266721033 has 2 divisors, whose sum is σ = 1266721034. Its totient is φ = 1266721032.

The previous prime is 1266721003. The next prime is 1266721037. The reversal of 1266721033 is 3301276621.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1201870224 + 64850809 = 34668^2 + 8053^2 .

It is a cyclic number.

It is not a de Polignac number, because 1266721033 - 2²⁵ = 1233166601 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1266720986 and 1266721004.

It is not a weakly prime, because it can be changed into another prime (1266721037) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 633360516 + 633360517.

It is an arithmetic number, because the mean of its divisors is an integer number (633360517).

Almost surely, 2^1266721033 is an apocalyptic number.

It is an amenable number.

1266721033 is a deficient number, since it is larger than the sum of its proper divisors (1).

1266721033 is an equidigital number, since it uses as much as digits as its factorization.

1266721033 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 9072, while the sum is 31.

The square root of 1266721033 is about 35591.0246129554. The cubic root of 1266721033 is about 1081.9993351688. Note that the first 3 decimals are identical.

Adding to 1266721033 its reverse (3301276621), we get a palindrome (4567997654).

The spelling of 1266721033 in words is "one billion, two hundred sixty-six million, seven hundred twenty-one thousand, thirty-three".