1522821 has 4 divisors (see below), whose sum is σ = 2030432. Its totient is φ = 1015212.

The previous prime is 1522811. The next prime is 1522837. The reversal of 1522821 is 1282251.

It is a happy number.

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 an emirpimes, since its reverse is a distinct semiprime: 1282251 = 3 ⋅427417.

It is not a de Polignac number, because 1522821 - 2⁵ = 1522789 is a prime.

It is a D-number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1522811) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 253801 + ... + 253806.

It is an arithmetic number, because the mean of its divisors is an integer number (507608).

2^1522821 is an apocalyptic number.

It is an amenable number.

1522821 is a deficient number, since it is larger than the sum of its proper divisors (507611).

1522821 is an equidigital number, since it uses as much as digits as its factorization.

1522821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 507610.

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

The square root of 1522821 is about 1234.0263368340. The cubic root of 1522821 is about 115.0490276144.

The spelling of 1522821 in words is "one million, five hundred twenty-two thousand, eight hundred twenty-one".