40878221 has 2 divisors, whose sum is σ = 40878222. Its totient is φ = 40878220.

The previous prime is 40878143. The next prime is 40878239. The reversal of 40878221 is 12287804.

40878221 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 31024900 + 9853321 = 5570^2 + 3139^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-40878221 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (40878121) 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, 20439110 + 20439111.

It is an arithmetic number, because the mean of its divisors is an integer number (20439111).

Almost surely, 2^40878221 is an apocalyptic number.

It is an amenable number.

40878221 is a deficient number, since it is larger than the sum of its proper divisors (1).

40878221 is an equidigital number, since it uses as much as digits as its factorization.

40878221 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 7168, while the sum is 32.

The square root of 40878221 is about 6393.6078234437. The cubic root of 40878221 is about 344.4799867320.

The spelling of 40878221 in words is "forty million, eight hundred seventy-eight thousand, two hundred twenty-one".