1265555340 has 360 divisors, whose sum is σ = 4692718800. Its totient is φ = 284643072.

The previous prime is 1265555339. The next prime is 1265555353. The reversal of 1265555340 is 435555621.

1265555340 is a `hidden beast` number, since 1 + 2 + 65 + 5 + 553 + 40 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 1265555295 and 1265555304.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 119 ways as a sum of consecutive naturals, for example, 8493586 + ... + 8493734.

It is an arithmetic number, because the mean of its divisors is an integer number (13035330).

Almost surely, 2^1265555340 is an apocalyptic number.

1265555340 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 1265555340, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2346359400).

1265555340 is an abundant number, since it is smaller than the sum of its proper divisors (3427163460).

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

1265555340 is a wasteful number, since it uses less digits than its factorization.

1265555340 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 291 (or 273 counting only the distinct ones).

The product of its (nonzero) digits is 90000, while the sum is 36.

The square root of 1265555340 is about 35574.6446222587. The cubic root of 1265555340 is about 1081.6673320124.

The spelling of 1265555340 in words is "one billion, two hundred sixty-five million, five hundred fifty-five thousand, three hundred forty".