2557521 has 8 divisors (see below), whose sum is σ = 3788960. Its totient is φ = 1704996.

The previous prime is 2557519. The next prime is 2557553. The reversal of 2557521 is 1257552.

It is a happy number.

It is not a de Polignac number, because 2557521 - 2¹ = 2557519 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27), and also a Moran number because the ratio is a prime number: 94723 = 2557521 / (2 + 5 + 5 + 7 + 5 + 2 + 1).

It is an Ulam number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2557501) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 47335 + ... + 47388.

It is an arithmetic number, because the mean of its divisors is an integer number (473620).

2^2557521 is an apocalyptic number.

It is an amenable number.

2557521 is a deficient number, since it is larger than the sum of its proper divisors (1231439).

2557521 is an equidigital number, since it uses as much as digits as its factorization.

2557521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 94732 (or 94726 counting only the distinct ones).

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

The square root of 2557521 is about 1599.2251248652. The cubic root of 2557521 is about 136.7539049069.

It can be divided in two parts, 255 and 7521, that added together give a 5-th power (7776 = 6⁵).

The spelling of 2557521 in words is "two million, five hundred fifty-seven thousand, five hundred twenty-one".