1265442979 has 2 divisors, whose sum is σ = 1265442980. Its totient is φ = 1265442978.

The previous prime is 1265442977. The next prime is 1265443009. The reversal of 1265442979 is 9792445621.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1265442979 - 2¹ = 1265442977 is a prime.

Together with 1265442977, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (1265442973) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 632721489 + 632721490.

It is an arithmetic number, because the mean of its divisors is an integer number (632721490).

Almost surely, 2^1265442979 is an apocalyptic number.

1265442979 is a deficient number, since it is larger than the sum of its proper divisors (1).

1265442979 is an equidigital number, since it uses as much as digits as its factorization.

1265442979 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1088640, while the sum is 49.

The square root of 1265442979 is about 35573.0653584984. The cubic root of 1265442979 is about 1081.6353194994.

The spelling of 1265442979 in words is "one billion, two hundred sixty-five million, four hundred forty-two thousand, nine hundred seventy-nine".