278785834643 has 2 divisors, whose sum is σ = 278785834644. Its totient is φ = 278785834642.

The previous prime is 278785834627. The next prime is 278785834661. The reversal of 278785834643 is 346438587872.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 278785834643 - 2⁴ = 278785834627 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 278785834643.

It is not a weakly prime, because it can be changed into another prime (278785834343) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 139392917321 + 139392917322.

It is an arithmetic number, because the mean of its divisors is an integer number (139392917322).

Almost surely, 2^278785834643 is an apocalyptic number.

278785834643 is a deficient number, since it is larger than the sum of its proper divisors (1).

278785834643 is an equidigital number, since it uses as much as digits as its factorization.

278785834643 is an evil number, because the sum of its binary digits is even.

The product of its digits is 216760320, while the sum is 65.

The spelling of 278785834643 in words is "two hundred seventy-eight billion, seven hundred eighty-five million, eight hundred thirty-four thousand, six hundred forty-three".