240742921 has 2 divisors, whose sum is σ = 240742922. Its totient is φ = 240742920.

The previous prime is 240742919. The next prime is 240742937. The reversal of 240742921 is 129247042.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 230432400 + 10310521 = 15180^2 + 3211^2 .

It is a cyclic number.

It is not a de Polignac number, because 240742921 - 2¹ = 240742919 is a prime.

It is a super-2 number, since 2×240742921² = 115914308023224482, which contains 22 as substring.

Together with 240742919, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (240742961) 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, 120371460 + 120371461.

It is an arithmetic number, because the mean of its divisors is an integer number (120371461).

Almost surely, 2^240742921 is an apocalyptic number.

It is an amenable number.

240742921 is a deficient number, since it is larger than the sum of its proper divisors (1).

240742921 is an equidigital number, since it uses as much as digits as its factorization.

240742921 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 31.

The square root of 240742921 is about 15515.8925299191. The cubic root of 240742921 is about 622.0870707607.

Adding to 240742921 its reverse (129247042), we get a palindrome (369989963).

The spelling of 240742921 in words is "two hundred forty million, seven hundred forty-two thousand, nine hundred twenty-one".