7505821 has 2 divisors, whose sum is σ = 7505822. Its totient is φ = 7505820.

The previous prime is 7505801. The next prime is 7505833. The reversal of 7505821 is 1285057.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 6996025 + 509796 = 2645^2 + 714^2 .

It is an emirp because it is prime and its reverse (1285057) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 7505821 - 2¹⁷ = 7374749 is a prime.

It is equal to p₅₀₈₆₃₆ and since 7505821 and 508636 have the same sum of digits, it is a Honaker prime.

It is a self number, because there is not a number n which added to its sum of digits gives 7505821.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (7505801) 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 as a sum of consecutive naturals, namely, 3752910 + 3752911.

It is an arithmetic number, because the mean of its divisors is an integer number (3752911).

Almost surely, 2^7505821 is an apocalyptic number.

It is an amenable number.

7505821 is a deficient number, since it is larger than the sum of its proper divisors (1).

7505821 is an equidigital number, since it uses as much as digits as its factorization.

7505821 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2800, while the sum is 28.

The square root of 7505821 is about 2739.6753457299. The cubic root of 7505821 is about 195.7940099506.

The spelling of 7505821 in words is "seven million, five hundred five thousand, eight hundred twenty-one".