7521521 has 8 divisors (see below), whose sum is σ = 8647104. Its totient is φ = 6408720.

The previous prime is 7521467. The next prime is 7521533. The reversal of 7521521 is 1251257.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-7521521 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (7521541) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1895 + ... + 4316.

It is an arithmetic number, because the mean of its divisors is an integer number (1080888).

Almost surely, 2^7521521 is an apocalyptic number.

It is an amenable number.

7521521 is a deficient number, since it is larger than the sum of its proper divisors (1125583).

7521521 is a wasteful number, since it uses less digits than its factorization.

7521521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6391.

The product of its digits is 700, while the sum is 23.

The square root of 7521521 is about 2742.5391519539. The cubic root of 7521521 is about 195.9304296334.

Adding to 7521521 its reverse (1251257), we get a palindrome (8772778).

The spelling of 7521521 in words is "seven million, five hundred twenty-one thousand, five hundred twenty-one".