1265352561 has 12 divisors (see below), whose sum is σ = 1993889040. Its totient is φ = 766880280.

The previous prime is 1265352547. The next prime is 1265352577. The reversal of 1265352561 is 1652535621.

1265352561 is a `hidden beast` number, since 1 + 2 + 65 + 35 + 2 + 561 = 666.

It is not a de Polignac number, because 1265352561 - 2⁷ = 1265352433 is a prime.

It is a super-2 number, since 2×1265352561² = 3202234207258517442, which contains 22 as substring.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (1265352541) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 6390571 + ... + 6390768.

It is an arithmetic number, because the mean of its divisors is an integer number (166157420).

Almost surely, 2^1265352561 is an apocalyptic number.

1265352561 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1265352561 is a deficient number, since it is larger than the sum of its proper divisors (728536479).

1265352561 is a wasteful number, since it uses less digits than its factorization.

1265352561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12781356 (or 12781353 counting only the distinct ones).

The product of its digits is 54000, while the sum is 36.

The square root of 1265352561 is about 35571.7944585313. The cubic root of 1265352561 is about 1081.6095573399.

The spelling of 1265352561 in words is "one billion, two hundred sixty-five million, three hundred fifty-two thousand, five hundred sixty-one".