2780000221 has 2 divisors, whose sum is σ = 2780000222. Its totient is φ = 2780000220.

The previous prime is 2780000213. The next prime is 2780000273. The reversal of 2780000221 is 1220000872.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1420234596 + 1359765625 = 37686^2 + 36875^2 .

It is a cyclic number.

It is not a de Polignac number, because 2780000221 - 2³ = 2780000213 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 2780000192 and 2780000201.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2780000281) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1390000110 + 1390000111.

It is an arithmetic number, because the mean of its divisors is an integer number (1390000111).

Almost surely, 2^2780000221 is an apocalyptic number.

It is an amenable number.

2780000221 is a deficient number, since it is larger than the sum of its proper divisors (1).

2780000221 is an equidigital number, since it uses as much as digits as its factorization.

2780000221 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 448, while the sum is 22.

The square root of 2780000221 is about 52725.7074016082. The cubic root of 2780000221 is about 1406.0959051405.

The spelling of 2780000221 in words is "two billion, seven hundred eighty million, two hundred twenty-one", and thus it is an aban number.