2821521 has 8 divisors (see below), whose sum is σ = 3776544. Its totient is φ = 1873760.

The previous prime is 2821517. The next prime is 2821537. The reversal of 2821521 is 1251282.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 2821521 - 2² = 2821517 is a prime.

It is not an unprimeable number, because it can be changed into a prime (2821501) 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, 831 + ... + 2516.

It is an arithmetic number, because the mean of its divisors is an integer number (472068).

2^2821521 is an apocalyptic number.

It is an amenable number.

2821521 is a deficient number, since it is larger than the sum of its proper divisors (955023).

2821521 is a wasteful number, since it uses less digits than its factorization.

2821521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3631.

The product of its digits is 320, while the sum is 21.

The square root of 2821521 is about 1679.7383724854. The cubic root of 2821521 is about 141.3061603500.

Subtracting from 2821521 its sum of digits (21), we obtain a triangular number (2821500 = T₂₃₇₅).

The spelling of 2821521 in words is "two million, eight hundred twenty-one thousand, five hundred twenty-one".