1270779905 has 4 divisors (see below), whose sum is σ = 1524935892. Its totient is φ = 1016623920.

The previous prime is 1270779893. The next prime is 1270779919. The reversal of 1270779905 is 5099770721.

It is a Cunningham number, because it is equal to 35648²+1.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 457446544 + 813333361 = 21388^2 + 28519^2 .

It is not a de Polignac number, because 1270779905 - 2⁶ = 1270779841 is a prime.

It is a super-2 number, since 2×1270779905² = 3229763133903618050, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1270779905.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 127077986 + ... + 127077995.

It is an arithmetic number, because the mean of its divisors is an integer number (381233973).

Almost surely, 2^1270779905 is an apocalyptic number.

It is an amenable number.

1270779905 is a deficient number, since it is larger than the sum of its proper divisors (254155987).

1270779905 is an equidigital number, since it uses as much as digits as its factorization.

1270779905 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 254155986.

The product of its (nonzero) digits is 277830, while the sum is 47.

The square root of 1270779905 is about 35648.0000140260. Note that the first 4 decimals coincide. The cubic root of 1270779905 is about 1083.1537631097.

The spelling of 1270779905 in words is "one billion, two hundred seventy million, seven hundred seventy-nine thousand, nine hundred five".