1266355257 has 8 divisors (see below), whose sum is σ = 1694894784. Its totient is φ = 841026288.

The previous prime is 1266355243. The next prime is 1266355261. The reversal of 1266355257 is 7525536621.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 1266355257 - 2⁴ = 1266355241 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1266350257) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 801718 + ... + 803295.

It is an arithmetic number, because the mean of its divisors is an integer number (211861848).

Almost surely, 2^1266355257 is an apocalyptic number.

It is an amenable number.

1266355257 is a deficient number, since it is larger than the sum of its proper divisors (428539527).

1266355257 is a wasteful number, since it uses less digits than its factorization.

1266355257 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1605279.

The product of its digits is 378000, while the sum is 42.

The square root of 1266355257 is about 35585.8856430467. The cubic root of 1266355257 is about 1081.8951797738.

The spelling of 1266355257 in words is "one billion, two hundred sixty-six million, three hundred fifty-five thousand, two hundred fifty-seven".