8125921 has 2 divisors, whose sum is σ = 8125922. Its totient is φ = 8125920.

The previous prime is 8125883. The next prime is 8125927. The reversal of 8125921 is 1295218.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 5198400 + 2927521 = 2280^2 + 1711^2 .

It is a cyclic number.

It is not a de Polignac number, because 8125921 - 2¹¹ = 8123873 is a prime.

8125921 is a lucky number.

It is a self number, because there is not a number n which added to its sum of digits gives 8125921.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (8125927) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4062960 + 4062961.

It is an arithmetic number, because the mean of its divisors is an integer number (4062961).

Almost surely, 2^8125921 is an apocalyptic number.

It is an amenable number.

8125921 is a deficient number, since it is larger than the sum of its proper divisors (1).

8125921 is an equidigital number, since it uses as much as digits as its factorization.

8125921 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1440, while the sum is 28.

The square root of 8125921 is about 2850.6001122571. The cubic root of 8125921 is about 201.0438837213.

It can be divided in two parts, 81 and 25921, that multiplied together give a square (2099601 = 1449²).

The spelling of 8125921 in words is "eight million, one hundred twenty-five thousand, nine hundred twenty-one".