7255521 has 32 divisors (see below), whose sum is σ = 13233920. Its totient is φ = 3825792.

The previous prime is 7255513. The next prime is 7255529. The reversal of 7255521 is 1255527.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (7255513) and next prime (7255529).

It is not a de Polignac number, because 7255521 - 2³ = 7255513 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a d-powerful number, because it can be written as 7⁸ + 2¹⁵ + 5⁵ + 5⁶ + 5⁸ + 2²⁰ + 1 .

7255521 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (7255529) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 981 + ... + 3933.

It is an arithmetic number, because the mean of its divisors is an integer number (413560).

Almost surely, 2^7255521 is an apocalyptic number.

It is an amenable number.

7255521 is a deficient number, since it is larger than the sum of its proper divisors (5978399).

7255521 is a wasteful number, since it uses less digits than its factorization.

7255521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2982 (or 2976 counting only the distinct ones).

The product of its digits is 3500, while the sum is 27.

The square root of 7255521 is about 2693.6074324222. The cubic root of 7255521 is about 193.5929485542.

It can be divided in two parts, 7255 and 521, that added together give a 5-th power (7776 = 6⁵).

The spelling of 7255521 in words is "seven million, two hundred fifty-five thousand, five hundred twenty-one".