1266497478 has 64 divisors (see below), whose sum is σ = 2971296000. Its totient is φ = 398768832.

The previous prime is 1266497471. The next prime is 1266497489. The reversal of 1266497478 is 8747946621.

1266497478 is a `hidden beast` number, since 1 + 26 + 64 + 97 + 478 = 666.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1266497471) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 387226 + ... + 390482.

It is an arithmetic number, because the mean of its divisors is an integer number (46426500).

Almost surely, 2^1266497478 is an apocalyptic number.

1266497478 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 1266497478, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1485648000).

1266497478 is an abundant number, since it is smaller than the sum of its proper divisors (1704798522).

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

1266497478 is a wasteful number, since it uses less digits than its factorization.

1266497478 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3666 (or 3660 counting only the distinct ones).

The product of its digits is 4064256, while the sum is 54.

The square root of 1266497478 is about 35587.8838651584. The cubic root of 1266497478 is about 1081.9356798503.

The spelling of 1266497478 in words is "one billion, two hundred sixty-six million, four hundred ninety-seven thousand, four hundred seventy-eight".