212278721 has 2 divisors, whose sum is σ = 212278722. Its totient is φ = 212278720.

The previous prime is 212278709. The next prime is 212278747. The reversal of 212278721 is 127872212.

212278721 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 131997121 + 80281600 = 11489^2 + 8960^2 .

It is a cyclic number.

It is not a de Polignac number, because 212278721 - 2¹⁰ = 212277697 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (212278751) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 106139360 + 106139361.

It is an arithmetic number, because the mean of its divisors is an integer number (106139361).

Almost surely, 2^212278721 is an apocalyptic number.

It is an amenable number.

212278721 is a deficient number, since it is larger than the sum of its proper divisors (1).

212278721 is an equidigital number, since it uses as much as digits as its factorization.

212278721 is an evil number, because the sum of its binary digits is even.

The product of its digits is 6272, while the sum is 32.

The square root of 212278721 is about 14569.7879531584. The cubic root of 212278721 is about 596.5343924436.

The spelling of 212278721 in words is "two hundred twelve million, two hundred seventy-eight thousand, seven hundred twenty-one".