1265266860 has 384 divisors, whose sum is σ = 4421910528. Its totient is φ = 266112000.

The previous prime is 1265266853. The next prime is 1265266861. The reversal of 1265266860 is 686625621.

It is not an unprimeable number, because it can be changed into a prime (1265266861) by changing a digit.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 17820625 + ... + 17820695.

It is an arithmetic number, because the mean of its divisors is an integer number (11515392).

Almost surely, 2^1265266860 is an apocalyptic number.

1265266860 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 1265266860, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2210955264).

1265266860 is an abundant number, since it is smaller than the sum of its proper divisors (3156643668).

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

1265266860 is a wasteful number, since it uses less digits than its factorization.

1265266860 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 205 (or 203 counting only the distinct ones).

The product of its (nonzero) digits is 207360, while the sum is 42.

The square root of 1265266860 is about 35570.5898179943. The cubic root of 1265266860 is about 1081.5851380288.

It can be divided in two parts, 126526 and 6860, that added together give a triangular number (133386 = T₅₁₆).

The spelling of 1265266860 in words is "one billion, two hundred sixty-five million, two hundred sixty-six thousand, eight hundred sixty".