1265743872 has 144 divisors (see below), whose sum is σ = 3743059320. Its totient is φ = 411844608.

The previous prime is 1265743867. The next prime is 1265743873. The reversal of 1265743872 is 2783475621.

1265743872 is a `hidden beast` number, since 1 + 2 + 6 + 574 + 3 + 8 + 72 = 666.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1265743873) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 791778 + ... + 793374.

Almost surely, 2^1265743872 is an apocalyptic number.

1265743872 is a gapful number since it is divisible by the number (12) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1265743872, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1871529660).

1265743872 is an abundant number, since it is smaller than the sum of its proper divisors (2477315448).

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

1265743872 is a wasteful number, since it uses less digits than its factorization.

1265743872 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1668 (or 1645 counting only the distinct ones).

The product of its digits is 564480, while the sum is 45.

The square root of 1265743872 is about 35577.2943322001. The cubic root of 1265743872 is about 1081.7210419723.

The spelling of 1265743872 in words is "one billion, two hundred sixty-five million, seven hundred forty-three thousand, eight hundred seventy-two".