7540021 has 4 divisors (see below), whose sum is σ = 7867872. Its totient is φ = 7212172.

The previous prime is 7540019. The next prime is 7540051. The reversal of 7540021 is 1200457.

7540021 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

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: 1200457 = 367 ⋅3271.

It is a cyclic number.

It is not a de Polignac number, because 7540021 - 2¹ = 7540019 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (7540051) 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, 163891 + ... + 163936.

It is an arithmetic number, because the mean of its divisors is an integer number (1966968).

Almost surely, 2^7540021 is an apocalyptic number.

It is an amenable number.

7540021 is a deficient number, since it is larger than the sum of its proper divisors (327851).

7540021 is a wasteful number, since it uses less digits than its factorization.

7540021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 327850.

The product of its (nonzero) digits is 280, while the sum is 19.

The square root of 7540021 is about 2745.9098674210. The cubic root of 7540021 is about 196.0909355209.

Adding to 7540021 its reverse (1200457), we get a palindrome (8740478).

The spelling of 7540021 in words is "seven million, five hundred forty thousand, twenty-one".