240340021 has 2 divisors, whose sum is σ = 240340022. Its totient is φ = 240340020.

The previous prime is 240340019. The next prime is 240340027. The reversal of 240340021 is 120043042.

240340021 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., 229522500 + 10817521 = 15150^2 + 3289^2 .

It is a cyclic number.

It is not a de Polignac number, because 240340021 - 2¹ = 240340019 is a prime.

Together with 240340019, it forms a pair of twin primes.

It is a junction number, because it is equal to n+sod(n) for n = 240339977 and 240340004.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (240340027) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 120170010 + 120170011.

It is an arithmetic number, because the mean of its divisors is an integer number (120170011).

Almost surely, 2^240340021 is an apocalyptic number.

It is an amenable number.

240340021 is a deficient number, since it is larger than the sum of its proper divisors (1).

240340021 is an equidigital number, since it uses as much as digits as its factorization.

240340021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 192, while the sum is 16.

The square root of 240340021 is about 15502.9036312557. The cubic root of 240340021 is about 621.7398416772.

Adding to 240340021 its reverse (120043042), we get a palindrome (360383063).

It can be divided in two parts, 2403 and 40021, that added together give a palindrome (42424).

The spelling of 240340021 in words is "two hundred forty million, three hundred forty thousand, twenty-one".