240542021 has 4 divisors (see below), whose sum is σ = 240606912. Its totient is φ = 240477132.

The previous prime is 240542011. The next prime is 240542041. The reversal of 240542021 is 120245042.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-240542021 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 240541984 and 240542002.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (240542011) 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 in 3 ways as a sum of consecutive naturals, for example, 26525 + ... + 34418.

It is an arithmetic number, because the mean of its divisors is an integer number (60151728).

Almost surely, 2^240542021 is an apocalyptic number.

It is an amenable number.

240542021 is a deficient number, since it is larger than the sum of its proper divisors (64891).

240542021 is an equidigital number, since it uses as much as digits as its factorization.

240542021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 64890.

The product of its (nonzero) digits is 640, while the sum is 20.

The square root of 240542021 is about 15509.4171715123. The cubic root of 240542021 is about 621.9139786886.

Adding to 240542021 its reverse (120245042), we get a palindrome (360787063).

The spelling of 240542021 in words is "two hundred forty million, five hundred forty-two thousand, twenty-one".