1266985440 has 144 divisors (see below), whose sum is σ = 4941282528. Its totient is φ = 289594368.

The previous prime is 1266985409. The next prime is 1266985459. The reversal of 1266985440 is 445896621.

1266985440 is a `hidden beast` number, since 12 + 6 + 6 + 98 + 544 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (144).

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

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 52767 + ... + 72926.

It is an arithmetic number, because the mean of its divisors is an integer number (34314462).

Almost surely, 2^1266985440 is an apocalyptic number.

1266985440 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1266985440 is an abundant number, since it is smaller than the sum of its proper divisors (3674297088).

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

1266985440 is a wasteful number, since it uses less digits than its factorization.

1266985440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 125721 (or 125710 counting only the distinct ones).

The product of its (nonzero) digits is 414720, while the sum is 45.

The square root of 1266985440 is about 35594.7389370957. The cubic root of 1266985440 is about 1082.0746130681.

The spelling of 1266985440 in words is "one billion, two hundred sixty-six million, nine hundred eighty-five thousand, four hundred forty".