1261312427 has 2 divisors, whose sum is σ = 1261312428. Its totient is φ = 1261312426.

The previous prime is 1261312417. The next prime is 1261312447. The reversal of 1261312427 is 7242131621.

It is a weak prime.

It is an emirp because it is prime and its reverse (7242131621) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1261312427 - 2²⁴ = 1244535211 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1261312427.

It is not a weakly prime, because it can be changed into another prime (1261312417) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 630656213 + 630656214.

It is an arithmetic number, because the mean of its divisors is an integer number (630656214).

Almost surely, 2^1261312427 is an apocalyptic number.

1261312427 is a deficient number, since it is larger than the sum of its proper divisors (1).

1261312427 is an equidigital number, since it uses as much as digits as its factorization.

1261312427 is an evil number, because the sum of its binary digits is even.

The product of its digits is 4032, while the sum is 29.

The square root of 1261312427 is about 35514.9606081719. The cubic root of 1261312427 is about 1080.4571758439.

The spelling of 1261312427 in words is "one billion, two hundred sixty-one million, three hundred twelve thousand, four hundred twenty-seven".