7540521 has 4 divisors (see below), whose sum is σ = 10054032. Its totient is φ = 5027012.

The previous prime is 7540517. The next prime is 7540529. The reversal of 7540521 is 1250457.

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 not a de Polignac number, because 7540521 - 2² = 7540517 is a prime.

It is a Curzon number.

7540521 is a lucky number.

It is a junction number, because it is equal to n+sod(n) for n = 7540491 and 7540500.

It is not an unprimeable number, because it can be changed into a prime (7540529) 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, 1256751 + ... + 1256756.

It is an arithmetic number, because the mean of its divisors is an integer number (2513508).

Almost surely, 2^7540521 is an apocalyptic number.

It is an amenable number.

7540521 is a deficient number, since it is larger than the sum of its proper divisors (2513511).

7540521 is a wasteful number, since it uses less digits than its factorization.

7540521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2513510.

The product of its (nonzero) digits is 1400, while the sum is 24.

The square root of 7540521 is about 2746.0009104150. Note that the first 3 decimals coincide. The cubic root of 7540521 is about 196.0952698723.

Adding to 7540521 its reverse (1250457), we get a palindrome (8790978).

Subtracting from 7540521 its reverse (1250457), we obtain a square (6290064 = 2508²).

The spelling of 7540521 in words is "seven million, five hundred forty thousand, five hundred twenty-one".