7722521 has 4 divisors (see below), whose sum is σ = 7774500. Its totient is φ = 7670544.

The previous prime is 7722479. The next prime is 7722527. The reversal of 7722521 is 1252277.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1252277 = 13 ⋅96329.

It can be written as a sum of positive squares in 2 ways, for example, as 1651225 + 6071296 = 1285^2 + 2464^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-7722521 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (7722527) 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, 25766 + ... + 26063.

It is an arithmetic number, because the mean of its divisors is an integer number (1943625).

Almost surely, 2^7722521 is an apocalyptic number.

It is an amenable number.

7722521 is a deficient number, since it is larger than the sum of its proper divisors (51979).

7722521 is a wasteful number, since it uses less digits than its factorization.

7722521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 51978.

The product of its digits is 1960, while the sum is 26.

The square root of 7722521 is about 2778.9424247364. The cubic root of 7722521 is about 197.6604133901.

Adding to 7722521 its reverse (1252277), we get a palindrome (8974798).

The spelling of 7722521 in words is "seven million, seven hundred twenty-two thousand, five hundred twenty-one".