278628887 has 2 divisors, whose sum is σ = 278628888. Its totient is φ = 278628886.

The previous prime is 278628851. The next prime is 278628893. The reversal of 278628887 is 788826872.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 278628887 - 2¹² = 278624791 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (278628817) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 139314443 + 139314444.

It is an arithmetic number, because the mean of its divisors is an integer number (139314444).

Almost surely, 2^278628887 is an apocalyptic number.

278628887 is a deficient number, since it is larger than the sum of its proper divisors (1).

278628887 is an equidigital number, since it uses as much as digits as its factorization.

278628887 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 4816896, while the sum is 56.

The square root of 278628887 is about 16692.1804147930. The cubic root of 278628887 is about 653.1436567307.

The spelling of 278628887 in words is "two hundred seventy-eight million, six hundred twenty-eight thousand, eight hundred eighty-seven".