1278061787 has 2 divisors, whose sum is σ = 1278061788. Its totient is φ = 1278061786.

The previous prime is 1278061721. The next prime is 1278061817. The reversal of 1278061787 is 7871608721.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 1278061787 - 2¹⁴ = 1278045403 is a prime.

It is not a weakly prime, because it can be changed into another prime (1278069787) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 639030893 + 639030894.

It is an arithmetic number, because the mean of its divisors is an integer number (639030894).

Almost surely, 2^1278061787 is an apocalyptic number.

1278061787 is a deficient number, since it is larger than the sum of its proper divisors (1).

1278061787 is an equidigital number, since it uses as much as digits as its factorization.

1278061787 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 263424, while the sum is 47.

The square root of 1278061787 is about 35749.9900279706. The cubic root of 1278061787 is about 1085.2187365066.

The spelling of 1278061787 in words is "one billion, two hundred seventy-eight million, sixty-one thousand, seven hundred eighty-seven".