1265513216 has 144 divisors (see below), whose sum is σ = 2877281568. Its totient is φ = 550502400.

The previous prime is 1265513213. The next prime is 1265513267. The reversal of 1265513216 is 6123155621.

It is a Harshad number since it is a multiple of its sum of digits (32).

It is not an unprimeable number, because it can be changed into a prime (1265513213) by changing a digit.

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 15 ways as a sum of consecutive naturals, for example, 11199176 + ... + 11199288.

It is an arithmetic number, because the mean of its divisors is an integer number (19981122).

Almost surely, 2^1265513216 is an apocalyptic number.

1265513216 is a gapful number since it is divisible by the number (16) 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 1265513216, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1438640784).

1265513216 is an abundant number, since it is smaller than the sum of its proper divisors (1611768352).

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

1265513216 is a wasteful number, since it uses less digits than its factorization.

1265513216 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 278 (or 264 counting only the distinct ones).

The product of its digits is 10800, while the sum is 32.

The square root of 1265513216 is about 35574.0525664423. The cubic root of 1265513216 is about 1081.6553307829.

Adding to 1265513216 its reverse (6123155621), we get a palindrome (7388668837).

The spelling of 1265513216 in words is "one billion, two hundred sixty-five million, five hundred thirteen thousand, two hundred sixteen".