1265720016 has 120 divisors (see below), whose sum is σ = 3609768960. Its totient is φ = 381877760.

The previous prime is 1265719999. The next prime is 1265720039. The reversal of 1265720016 is 6100275621.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 2224180 + ... + 2224748.

It is an arithmetic number, because the mean of its divisors is an integer number (30081408).

Almost surely, 2^1265720016 is an apocalyptic number.

1265720016 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 1265720016, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1804884480).

1265720016 is an abundant number, since it is smaller than the sum of its proper divisors (2344048944).

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

1265720016 is a wasteful number, since it uses less digits than its factorization.

1265720016 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 985 (or 968 counting only the distinct ones).

The product of its (nonzero) digits is 5040, while the sum is 30.

The square root of 1265720016 is about 35576.9590606055. The cubic root of 1265720016 is about 1081.7142460478.

Adding to 1265720016 its reverse (6100275621), we get a palindrome (7365995637).

The spelling of 1265720016 in words is "one billion, two hundred sixty-five million, seven hundred twenty thousand, sixteen".