7240021 has 4 divisors (see below), whose sum is σ = 7394112. Its totient is φ = 7085932.

The previous prime is 7240001. The next prime is 7240031. The reversal of 7240021 is 1200427.

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, and also an emirpimes, since its reverse is a distinct semiprime: 1200427 = 47 ⋅25541.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-7240021 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 7239977 and 7240004.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (7240001) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 76975 + ... + 77068.

It is an arithmetic number, because the mean of its divisors is an integer number (1848528).

Almost surely, 2^7240021 is an apocalyptic number.

It is an amenable number.

7240021 is a deficient number, since it is larger than the sum of its proper divisors (154091).

7240021 is a wasteful number, since it uses less digits than its factorization.

7240021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 154090.

The product of its (nonzero) digits is 112, while the sum is 16.

The square root of 7240021 is about 2690.7287117062. The cubic root of 7240021 is about 193.4549924589.

Adding to 7240021 its reverse (1200427), we get a palindrome (8440448).

The spelling of 7240021 in words is "seven million, two hundred forty thousand, twenty-one".