278990057 has 2 divisors, whose sum is σ = 278990058. Its totient is φ = 278990056.

The previous prime is 278990051. The next prime is 278990059. The reversal of 278990057 is 750099872.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 265820416 + 13169641 = 16304^2 + 3629^2 .

It is a cyclic number.

It is not a de Polignac number, because 278990057 - 2²² = 274795753 is a prime.

Together with 278990059, it forms a pair of twin primes.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 278989993 and 278990020.

It is not a weakly prime, because it can be changed into another prime (278990051) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 139495028 + 139495029.

It is an arithmetic number, because the mean of its divisors is an integer number (139495029).

Almost surely, 2^278990057 is an apocalyptic number.

It is an amenable number.

278990057 is a deficient number, since it is larger than the sum of its proper divisors (1).

278990057 is an equidigital number, since it uses as much as digits as its factorization.

278990057 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 317520, while the sum is 47.

The square root of 278990057 is about 16702.9954499186. The cubic root of 278990057 is about 653.4257452637.

The spelling of 278990057 in words is "two hundred seventy-eight million, nine hundred ninety thousand, fifty-seven".