1622521 has 4 divisors (see below), whose sum is σ = 1678500. Its totient is φ = 1566544.

The previous prime is 1622483. The next prime is 1622549. The reversal of 1622521 is 1252261.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1252261 = 449 ⋅2789.

It can be written as a sum of positive squares in 2 ways, for example, as 622521 + 1000000 = 789^2 + 1000^2 .

It is a cyclic number.

It is not a de Polignac number, because 1622521 - 2⁹ = 1622009 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1622591) 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, 27946 + ... + 28003.

It is an arithmetic number, because the mean of its divisors is an integer number (419625).

2^1622521 is an apocalyptic number.

It is an amenable number.

1622521 is a deficient number, since it is larger than the sum of its proper divisors (55979).

1622521 is an equidigital number, since it uses as much as digits as its factorization.

1622521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 55978.

The product of its digits is 240, while the sum is 19.

The square root of 1622521 is about 1273.7821634801. The cubic root of 1622521 is about 117.5069197675.

Adding to 1622521 its reverse (1252261), we get a palindrome (2874782).

It can be divided in two parts, 16225 and 21, that multiplied together give a triangular number (340725 = T₈₂₅).

The spelling of 1622521 in words is "one million, six hundred twenty-two thousand, five hundred twenty-one".