1265615645 has 8 divisors (see below), whose sum is σ = 1735701504. Its totient is φ = 867850704.

The previous prime is 1265615633. The next prime is 1265615647. The reversal of 1265615645 is 5465165621.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 1265615645 - 2²⁸ = 997180189 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1265615647) 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, 18080189 + ... + 18080258.

It is an arithmetic number, because the mean of its divisors is an integer number (216962688).

Almost surely, 2^1265615645 is an apocalyptic number.

It is an amenable number.

1265615645 is a deficient number, since it is larger than the sum of its proper divisors (470085859).

1265615645 is an equidigital number, since it uses as much as digits as its factorization.

1265615645 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 36160459.

The product of its digits is 216000, while the sum is 41.

The square root of 1265615645 is about 35575.4921961735. The cubic root of 1265615645 is about 1081.6845125892.

The spelling of 1265615645 in words is "one billion, two hundred sixty-five million, six hundred fifteen thousand, six hundred forty-five".