7721889 has 16 divisors (see below), whose sum is σ = 11934720. Its totient is φ = 4349520.

The previous prime is 7721873. The next prime is 7721891. The reversal of 7721889 is 9881277.

It is not a de Polignac number, because 7721889 - 2⁴ = 7721873 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 7721889.

It is not an unprimeable number, because it can be changed into a prime (7721849) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1099 + ... + 4080.

It is an arithmetic number, because the mean of its divisors is an integer number (745920).

Almost surely, 2^7721889 is an apocalyptic number.

It is an amenable number.

7721889 is a deficient number, since it is larger than the sum of its proper divisors (4212831).

7721889 is a wasteful number, since it uses less digits than its factorization.

7721889 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5260.

The product of its digits is 56448, while the sum is 42.

The square root of 7721889 is about 2778.8287100863. The cubic root of 7721889 is about 197.6550211618.

The spelling of 7721889 in words is "seven million, seven hundred twenty-one thousand, eight hundred eighty-nine".