1265440551 has 8 divisors (see below), whose sum is σ = 1698428544. Its totient is φ = 838039800.

The previous prime is 1265440511. The next prime is 1265440559. The reversal of 1265440551 is 1550445621.

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

It is not a de Polignac number, because 1265440551 - 2⁶ = 1265440487 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1265440559) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1396281 + ... + 1397186.

It is an arithmetic number, because the mean of its divisors is an integer number (212303568).

Almost surely, 2^1265440551 is an apocalyptic number.

1265440551 is a deficient number, since it is larger than the sum of its proper divisors (432987993).

1265440551 is a wasteful number, since it uses less digits than its factorization.

1265440551 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2793621.

The product of its (nonzero) digits is 24000, while the sum is 33.

The square root of 1265440551 is about 35573.0312315383. The cubic root of 1265440551 is about 1081.6346277226.

The spelling of 1265440551 in words is "one billion, two hundred sixty-five million, four hundred forty thousand, five hundred fifty-one".