1266272865 has 192 divisors, whose sum is σ = 2734905600. Its totient is φ = 551992320.

The previous prime is 1266272851. The next prime is 1266272869. The reversal of 1266272865 is 5682726621.

1266272865 is a `hidden beast` number, since 12 + 6 + 627 + 2 + 8 + 6 + 5 = 666.

It is not a de Polignac number, because 1266272865 - 2⁶ = 1266272801 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 1266272865.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1266272869) by changing a digit.

It is a polite number, since it can be written in 191 ways as a sum of consecutive naturals, for example, 14227741 + ... + 14227829.

It is an arithmetic number, because the mean of its divisors is an integer number (14244300).

Almost surely, 2^1266272865 is an apocalyptic number.

1266272865 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1266272865 is an abundant number, since it is smaller than the sum of its proper divisors (1468632735).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1266272865 is a wasteful number, since it uses less digits than its factorization.

1266272865 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 205 (or 188 counting only the distinct ones).

The product of its digits is 483840, while the sum is 45.

The square root of 1266272865 is about 35584.7279742307. The cubic root of 1266272865 is about 1081.8717157312.

The spelling of 1266272865 in words is "one billion, two hundred sixty-six million, two hundred seventy-two thousand, eight hundred sixty-five".