1278257977 has 2 divisors, whose sum is σ = 1278257978. Its totient is φ = 1278257976.

The previous prime is 1278257909. The next prime is 1278257983. The reversal of 1278257977 is 7797528721.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1251673641 + 26584336 = 35379^2 + 5156^2 .

It is a cyclic number.

It is not a de Polignac number, because 1278257977 - 2²³ = 1269869369 is a prime.

It is not a weakly prime, because it can be changed into another prime (1278257777) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 639128988 + 639128989.

It is an arithmetic number, because the mean of its divisors is an integer number (639128989).

Almost surely, 2^1278257977 is an apocalyptic number.

It is an amenable number.

1278257977 is a deficient number, since it is larger than the sum of its proper divisors (1).

1278257977 is an equidigital number, since it uses as much as digits as its factorization.

1278257977 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3457440, while the sum is 55.

The square root of 1278257977 is about 35752.7338395262. The cubic root of 1278257977 is about 1085.2742628181.

The spelling of 1278257977 in words is "one billion, two hundred seventy-eight million, two hundred fifty-seven thousand, nine hundred seventy-seven".