7121808 has 90 divisors (see below), whose sum is σ = 21188934. Its totient is φ = 2232576.

The previous prime is 7121801. The next prime is 7121809. The reversal of 7121808 is 8081217.

It can be written as a sum of positive squares in only one way, i.e., 6290064 + 831744 = 2508^2 + 912^2 .

It is a super-3 number, since 3×7121808³ (a number of 22 digits) contains 333 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (7121801) 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 17 ways as a sum of consecutive naturals, for example, 51916 + ... + 52052.

Almost surely, 2^7121808 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 7121808, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (10594467).

7121808 is an abundant number, since it is smaller than the sum of its proper divisors (14067126).

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

7121808 is a wasteful number, since it uses less digits than its factorization.

7121808 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 189 (or 161 counting only the distinct ones).

The product of its (nonzero) digits is 896, while the sum is 27.

The square root of 7121808 is about 2668.6715796441. The cubic root of 7121808 is about 192.3963167965.

The spelling of 7121808 in words is "seven million, one hundred twenty-one thousand, eight hundred eight".