1265516340 has 96 divisors (see below), whose sum is σ = 3886202880. Its totient is φ = 305155200.

The previous prime is 1265516339. The next prime is 1265516341. The reversal of 1265516340 is 436155621.

It is an interprime number because it is at equal distance from previous prime (1265516339) and next prime (1265516341).

It is a Harshad number since it is a multiple of its sum of digits (33).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1265516341) 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, 121041 + ... + 131079.

It is an arithmetic number, because the mean of its divisors is an integer number (40481280).

Almost surely, 2^1265516340 is an apocalyptic number.

1265516340 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 1265516340, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1943101440).

1265516340 is an abundant number, since it is smaller than the sum of its proper divisors (2620686540).

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

1265516340 is a wasteful number, since it uses less digits than its factorization.

1265516340 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10253 (or 10251 counting only the distinct ones).

The product of its (nonzero) digits is 21600, while the sum is 33.

The square root of 1265516340 is about 35574.0964748228. The cubic root of 1265516340 is about 1081.6562208272.

The spelling of 1265516340 in words is "one billion, two hundred sixty-five million, five hundred sixteen thousand, three hundred forty".