1265205984 has 48 divisors (see below), whose sum is σ = 3795619968. Its totient is φ = 361487232.

The previous prime is 1265205979. The next prime is 1265206021. The reversal of 1265205984 is 4895025621.

It is a tau number, because it is divible by the number of its divisors (48).

It is a Harshad number since it is a multiple of its sum of digits (42).

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 7 ways as a sum of consecutive naturals, for example, 940702 + ... + 942045.

It is an arithmetic number, because the mean of its divisors is an integer number (79075416).

Almost surely, 2^1265205984 is an apocalyptic number.

1265205984 is a gapful number since it is divisible by the number (14) formed by its first and last digit.

It is an amenable number.

1265205984 is an abundant number, since it is smaller than the sum of its proper divisors (2530413984).

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

1265205984 is a wasteful number, since it uses less digits than its factorization.

1265205984 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1882767 (or 1882759 counting only the distinct ones).

The product of its (nonzero) digits is 172800, while the sum is 42.

The square root of 1265205984 is about 35569.7341007773. The cubic root of 1265205984 is about 1081.5677915873.

The spelling of 1265205984 in words is "one billion, two hundred sixty-five million, two hundred five thousand, nine hundred eighty-four".