7828821 has 72 divisors (see below), whose sum is σ = 15491840. Its totient is φ = 3706560.

The previous prime is 7828783. The next prime is 7828841. The reversal of 7828821 is 1288287.

It is not a de Polignac number, because 7828821 - 2¹¹ = 7826773 is a prime.

It is a super-2 number, since 2×7828821² = 122580876500082, which contains 22 as substring.

It is a nialpdrome in base 16.

It is a zygodrome in base 16.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (7828841) by changing a digit.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 99060 + ... + 99138.

Almost surely, 2^7828821 is an apocalyptic number.

It is an amenable number.

7828821 is a deficient number, since it is larger than the sum of its proper divisors (7663019).

7828821 is a wasteful number, since it uses less digits than its factorization.

7828821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 127 (or 113 counting only the distinct ones).

The product of its digits is 14336, while the sum is 36.

The square root of 7828821 is about 2798.0030378826. The cubic root of 7828821 is about 198.5632112407.

It can be divided in two parts, 7828 and 821, that added together give a square (8649 = 93²).

The spelling of 7828821 in words is "seven million, eight hundred twenty-eight thousand, eight hundred twenty-one".