1278634543 has 2 divisors, whose sum is σ = 1278634544. Its totient is φ = 1278634542.

The previous prime is 1278634531. The next prime is 1278634547. The reversal of 1278634543 is 3454368721.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 1278634543 - 2⁹ = 1278634031 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1278634543.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1278634547) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 639317271 + 639317272.

It is an arithmetic number, because the mean of its divisors is an integer number (639317272).

Almost surely, 2^1278634543 is an apocalyptic number.

1278634543 is a deficient number, since it is larger than the sum of its proper divisors (1).

1278634543 is an equidigital number, since it uses as much as digits as its factorization.

1278634543 is an evil number, because the sum of its binary digits is even.

The product of its digits is 483840, while the sum is 43.

The square root of 1278634543 is about 35757.9997063594. Note that the first 3 decimals coincide. The cubic root of 1278634543 is about 1085.3808237968.

The spelling of 1278634543 in words is "one billion, two hundred seventy-eight million, six hundred thirty-four thousand, five hundred forty-three".