8121820 has 24 divisors (see below), whose sum is σ = 19492704. Its totient is φ = 2784576.

The previous prime is 8121811. The next prime is 8121821. The reversal of 8121820 is 281218.

It is a super-2 number, since 2×8121820² = 131927920224800, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 8121791 and 8121800.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (8121821) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 28867 + ... + 29146.

It is an arithmetic number, because the mean of its divisors is an integer number (812196).

Almost surely, 2^8121820 is an apocalyptic number.

It is an amenable number.

8121820 is an abundant number, since it is smaller than the sum of its proper divisors (11370884).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

8121820 is a wasteful number, since it uses less digits than its factorization.

8121820 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 58029 (or 58027 counting only the distinct ones).

The product of its (nonzero) digits is 256, while the sum is 22.

The square root of 8121820 is about 2849.8806992574. The cubic root of 8121820 is about 201.0100570036.

The spelling of 8121820 in words is "eight million, one hundred twenty-one thousand, eight hundred twenty".