240978821 has 2 divisors, whose sum is σ = 240978822. Its totient is φ = 240978820.

The previous prime is 240978799. The next prime is 240978847. The reversal of 240978821 is 128879042.

240978821 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., 233661796 + 7317025 = 15286^2 + 2705^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-240978821 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (240978421) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 120489410 + 120489411.

It is an arithmetic number, because the mean of its divisors is an integer number (120489411).

Almost surely, 2^240978821 is an apocalyptic number.

It is an amenable number.

240978821 is a deficient number, since it is larger than the sum of its proper divisors (1).

240978821 is an equidigital number, since it uses as much as digits as its factorization.

240978821 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 64512, while the sum is 41.

The square root of 240978821 is about 15523.4925516135. The cubic root of 240978821 is about 622.2901953673.

The spelling of 240978821 in words is "two hundred forty million, nine hundred seventy-eight thousand, eight hundred twenty-one".