1278965957 has 2 divisors, whose sum is σ = 1278965958. Its totient is φ = 1278965956.

The previous prime is 1278965953. The next prime is 1278966023. The reversal of 1278965957 is 7595698721.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1083133921 + 195832036 = 32911^2 + 13994^2 .

It is a cyclic number.

It is not a de Polignac number, because 1278965957 - 2² = 1278965953 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1278965896 and 1278965905.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1278965953) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 639482978 + 639482979.

It is an arithmetic number, because the mean of its divisors is an integer number (639482979).

Almost surely, 2^1278965957 is an apocalyptic number.

It is an amenable number.

1278965957 is a deficient number, since it is larger than the sum of its proper divisors (1).

1278965957 is an equidigital number, since it uses as much as digits as its factorization.

1278965957 is an evil number, because the sum of its binary digits is even.

The product of its digits is 9525600, while the sum is 59.

The square root of 1278965957 is about 35762.6335299849. The cubic root of 1278965957 is about 1085.4745903148.

The spelling of 1278965957 in words is "one billion, two hundred seventy-eight million, nine hundred sixty-five thousand, nine hundred fifty-seven".