1265978481 has 4 divisors (see below), whose sum is σ = 1687971312. Its totient is φ = 843985652.

The previous prime is 1265978477. The next prime is 1265978509. The reversal of 1265978481 is 1848795621.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 1265978481 - 2² = 1265978477 is a prime.

It is a super-2 number, since 2×1265978481² = 3205403028710134722, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (1265978471) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 210996411 + ... + 210996416.

It is an arithmetic number, because the mean of its divisors is an integer number (421992828).

Almost surely, 2^1265978481 is an apocalyptic number.

It is an amenable number.

1265978481 is a deficient number, since it is larger than the sum of its proper divisors (421992831).

1265978481 is an equidigital number, since it uses as much as digits as its factorization.

1265978481 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 421992830.

The product of its digits is 967680, while the sum is 51.

The square root of 1265978481 is about 35580.5913525900. The cubic root of 1265978481 is about 1081.7878711361.

The spelling of 1265978481 in words is "one billion, two hundred sixty-five million, nine hundred seventy-eight thousand, four hundred eighty-one".