278117901857 has 2 divisors, whose sum is σ = 278117901858. Its totient is φ = 278117901856.

The previous prime is 278117901829. The next prime is 278117901881. The reversal of 278117901857 is 758109711872.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 267960487201 + 10157414656 = 517649^2 + 100784^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-278117901857 is a prime.

It is not a weakly prime, because it can be changed into another prime (278117901557) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 139058950928 + 139058950929.

It is an arithmetic number, because the mean of its divisors is an integer number (139058950929).

Almost surely, 2^278117901857 is an apocalyptic number.

It is an amenable number.

278117901857 is a deficient number, since it is larger than the sum of its proper divisors (1).

278117901857 is an equidigital number, since it uses as much as digits as its factorization.

278117901857 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1975680, while the sum is 56.

The spelling of 278117901857 in words is "two hundred seventy-eight billion, one hundred seventeen million, nine hundred one thousand, eight hundred fifty-seven".