1266540555 has 32 divisors (see below), whose sum is σ = 2325616128. Its totient is φ = 576576000.

The previous prime is 1266540503. The next prime is 1266540559. The reversal of 1266540555 is 5550456621.

It is a happy number.

It is not a de Polignac number, because 1266540555 - 2⁶ = 1266540491 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1266540559) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 280 + ... + 50330.

It is an arithmetic number, because the mean of its divisors is an integer number (72675504).

Almost surely, 2^1266540555 is an apocalyptic number.

1266540555 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

1266540555 is a deficient number, since it is larger than the sum of its proper divisors (1059075573).

1266540555 is a wasteful number, since it uses less digits than its factorization.

1266540555 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 50307.

The product of its (nonzero) digits is 180000, while the sum is 39.

The square root of 1266540555 is about 35588.4890800382. The cubic root of 1266540555 is about 1081.9479462295.

The spelling of 1266540555 in words is "one billion, two hundred sixty-six million, five hundred forty thousand, five hundred fifty-five".