7520921 has 2 divisors, whose sum is σ = 7520922. Its totient is φ = 7520920.

The previous prime is 7520911. The next prime is 7520927. The reversal of 7520921 is 1290257.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 5736025 + 1784896 = 2395^2 + 1336^2 .

It is an emirp because it is prime and its reverse (1290257) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-7520921 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (7520927) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3760460 + 3760461.

It is an arithmetic number, because the mean of its divisors is an integer number (3760461).

Almost surely, 2^7520921 is an apocalyptic number.

It is an amenable number.

7520921 is a deficient number, since it is larger than the sum of its proper divisors (1).

7520921 is an equidigital number, since it uses as much as digits as its factorization.

7520921 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1260, while the sum is 26.

The square root of 7520921 is about 2742.4297620905. The cubic root of 7520921 is about 195.9252196330.

The spelling of 7520921 in words is "seven million, five hundred twenty thousand, nine hundred twenty-one".