1266722993 has 2 divisors, whose sum is σ = 1266722994. Its totient is φ = 1266722992.

The previous prime is 1266722923. The next prime is 1266723037. The reversal of 1266722993 is 3992276621.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 691058944 + 575664049 = 26288^2 + 23993^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1266722993 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (1266722923) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 633361496 + 633361497.

It is an arithmetic number, because the mean of its divisors is an integer number (633361497).

Almost surely, 2^1266722993 is an apocalyptic number.

It is an amenable number.

1266722993 is a deficient number, since it is larger than the sum of its proper divisors (1).

1266722993 is an equidigital number, since it uses as much as digits as its factorization.

1266722993 is an evil number, because the sum of its binary digits is even.

The product of its digits is 489888, while the sum is 47.

The square root of 1266722993 is about 35591.0521479767. The cubic root of 1266722993 is about 1081.9998932285. Note that the first 3 decimals are identical.

The spelling of 1266722993 in words is "one billion, two hundred sixty-six million, seven hundred twenty-two thousand, nine hundred ninety-three".