1265297280 has 256 divisors, whose sum is σ = 4384074240. Its totient is φ = 308551680.

The previous prime is 1265297279. The next prime is 1265297287. The reversal of 1265297280 is 827925621.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1265297287) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 4068325 + ... + 4068635.

It is an arithmetic number, because the mean of its divisors is an integer number (17125290).

Almost surely, 2^1265297280 is an apocalyptic number.

1265297280 is a gapful number since it is divisible by the number (10) 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 1265297280, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2192037120).

1265297280 is an abundant number, since it is smaller than the sum of its proper divisors (3118776960).

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

1265297280 is a wasteful number, since it uses less digits than its factorization.

1265297280 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 509 (or 497 counting only the distinct ones).

The product of its (nonzero) digits is 120960, while the sum is 42.

The square root of 1265297280 is about 35571.0174158682. The cubic root of 1265297280 is about 1081.5938059120.

The spelling of 1265297280 in words is "one billion, two hundred sixty-five million, two hundred ninety-seven thousand, two hundred eighty".