7865521 has 4 divisors (see below), whose sum is σ = 7871344. Its totient is φ = 7859700.

The previous prime is 7865519. The next prime is 7865527. The reversal of 7865521 is 1255687.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 7865521 - 2¹ = 7865519 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (7865527) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 286 + ... + 3976.

It is an arithmetic number, because the mean of its divisors is an integer number (1967836).

Almost surely, 2^7865521 is an apocalyptic number.

It is an amenable number.

7865521 is a deficient number, since it is larger than the sum of its proper divisors (5823).

7865521 is a wasteful number, since it uses less digits than its factorization.

7865521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5822.

The product of its digits is 16800, while the sum is 34.

The square root of 7865521 is about 2804.5536186709. The cubic root of 7865521 is about 198.8730029838.

The spelling of 7865521 in words is "seven million, eight hundred sixty-five thousand, five hundred twenty-one".