2278109921 has 2 divisors, whose sum is σ = 2278109922. Its totient is φ = 2278109920.

The previous prime is 2278109903. The next prime is 2278109923. The reversal of 2278109921 is 1299018722.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1762320400 + 515789521 = 41980^2 + 22711^2 .

It is a cyclic number.

It is not a de Polignac number, because 2278109921 - 2¹⁸ = 2277847777 is a prime.

Together with 2278109923, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (2278109923) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1139054960 + 1139054961.

It is an arithmetic number, because the mean of its divisors is an integer number (1139054961).

Almost surely, 2^2278109921 is an apocalyptic number.

It is an amenable number.

2278109921 is a deficient number, since it is larger than the sum of its proper divisors (1).

2278109921 is an equidigital number, since it uses as much as digits as its factorization.

2278109921 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 36288, while the sum is 41.

The square root of 2278109921 is about 47729.5497674135. The cubic root of 2278109921 is about 1315.8050790609.

The spelling of 2278109921 in words is "two billion, two hundred seventy-eight million, one hundred nine thousand, nine hundred twenty-one".