1265238787 has 16 divisors (see below), whose sum is σ = 1367731872. Its totient is φ = 1166077440.

The previous prime is 1265238781. The next prime is 1265238811. The reversal of 1265238787 is 7878325621.

It is a cyclic number.

It is not a de Polignac number, because 1265238787 - 2⁷ = 1265238659 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1265238787.

It is not an unprimeable number, because it can be changed into a prime (1265238781) 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, 193837 + ... + 200257.

It is an arithmetic number, because the mean of its divisors is an integer number (85483242).

Almost surely, 2^1265238787 is an apocalyptic number.

1265238787 is a gapful number since it is divisible by the number (17) formed by its first and last digit.

1265238787 is a deficient number, since it is larger than the sum of its proper divisors (102493085).

1265238787 is a wasteful number, since it uses less digits than its factorization.

1265238787 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6678.

The product of its digits is 1128960, while the sum is 49.

The square root of 1265238787 is about 35570.1952060992. The cubic root of 1265238787 is about 1081.5771387771.

The spelling of 1265238787 in words is "one billion, two hundred sixty-five million, two hundred thirty-eight thousand, seven hundred eighty-seven".