240817921 has 2 divisors, whose sum is σ = 240817922. Its totient is φ = 240817920.

The previous prime is 240817909. The next prime is 240817933. The reversal of 240817921 is 129718042.

It is a balanced prime because it is at equal distance from previous prime (240817909) and next prime (240817933).

It can be written as a sum of positive squares in only one way, i.e., 217149696 + 23668225 = 14736^2 + 4865^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-240817921 is a prime.

It is not a weakly prime, because it can be changed into another prime (240817961) 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, 120408960 + 120408961.

It is an arithmetic number, because the mean of its divisors is an integer number (120408961).

Almost surely, 2^240817921 is an apocalyptic number.

240817921 is the 8960-th hex number.

It is an amenable number.

240817921 is a deficient number, since it is larger than the sum of its proper divisors (1).

240817921 is an equidigital number, since it uses as much as digits as its factorization.

240817921 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 8064, while the sum is 34.

The square root of 240817921 is about 15518.3092184684. The cubic root of 240817921 is about 622.1516648180.

The spelling of 240817921 in words is "two hundred forty million, eight hundred seventeen thousand, nine hundred twenty-one".