1265353809 has 16 divisors (see below), whose sum is σ = 1864052352. Its totient is φ = 759427328.

The previous prime is 1265353807. The next prime is 1265353883. The reversal of 1265353809 is 9083535621.

It is a cyclic number.

It is not a de Polignac number, because 1265353809 - 2¹ = 1265353807 is a prime.

It is a super-2 number, since 2×1265353809² = 3202240523901616962, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (1265353807) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 538194 + ... + 540539.

It is an arithmetic number, because the mean of its divisors is an integer number (116503272).

Almost surely, 2^1265353809 is an apocalyptic number.

It is an amenable number.

1265353809 is a deficient number, since it is larger than the sum of its proper divisors (598698543).

1265353809 is a wasteful number, since it uses less digits than its factorization.

1265353809 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1078776.

The product of its (nonzero) digits is 194400, while the sum is 42.

The square root of 1265353809 is about 35571.8120005152. The cubic root of 1265353809 is about 1081.6099129320.

The spelling of 1265353809 in words is "one billion, two hundred sixty-five million, three hundred fifty-three thousand, eight hundred nine".