1265303440 has 40 divisors (see below), whose sum is σ = 3036734208. Its totient is φ = 489793920.

The previous prime is 1265303411. The next prime is 1265303441. The reversal of 1265303440 is 443035621.

It is a tau number, because it is divible by the number of its divisors (40).

It is a Smith number, since the sum of its digits (28) coincides with the sum of the digits of its prime factors.

It is a junction number, because it is equal to n+sod(n) for n = 1265303399 and 1265303408.

It is not an unprimeable number, because it can be changed into a prime (1265303441) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 252622 + ... + 257581.

Almost surely, 2^1265303440 is an apocalyptic number.

1265303440 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1265303440 is an abundant number, since it is smaller than the sum of its proper divisors (1771430768).

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

1265303440 is a wasteful number, since it uses less digits than its factorization.

1265303440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 510247 (or 510241 counting only the distinct ones).

The product of its (nonzero) digits is 8640, while the sum is 28.

The square root of 1265303440 is about 35571.1040031090. The cubic root of 1265303440 is about 1081.5955611272.

The spelling of 1265303440 in words is "one billion, two hundred sixty-five million, three hundred three thousand, four hundred forty".