1266381157 has 2 divisors, whose sum is σ = 1266381158. Its totient is φ = 1266381156.

The previous prime is 1266381101. The next prime is 1266381197. The reversal of 1266381157 is 7511836621.

It is a happy number.

It is an a-pointer prime, because the next prime (1266381197) can be obtained adding 1266381157 to its sum of digits (40).

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1261741441 + 4639716 = 35521^2 + 2154^2 .

It is a cyclic number.

It is not a de Polignac number, because 1266381157 - 2⁷ = 1266381029 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1266381197) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 633190578 + 633190579.

It is an arithmetic number, because the mean of its divisors is an integer number (633190579).

Almost surely, 2^1266381157 is an apocalyptic number.

It is an amenable number.

1266381157 is a deficient number, since it is larger than the sum of its proper divisors (1).

1266381157 is an equidigital number, since it uses as much as digits as its factorization.

1266381157 is an evil number, because the sum of its binary digits is even.

The product of its digits is 60480, while the sum is 40.

The square root of 1266381157 is about 35586.2495495100. The cubic root of 1266381157 is about 1081.9025555066.

The spelling of 1266381157 in words is "one billion, two hundred sixty-six million, three hundred eighty-one thousand, one hundred fifty-seven".