7721865 has 32 divisors (see below), whose sum is σ = 14031360. Its totient is φ = 4027392.

The previous prime is 7721849. The next prime is 7721873. The reversal of 7721865 is 5681277.

7721865 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 7721865 - 2⁴ = 7721849 is a prime.

It is a Smith number, since the sum of its digits (36) coincides with the sum of the digits of its prime factors.

It is a congruent number.

It is an unprimeable number.

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 31 ways as a sum of consecutive naturals, for example, 5737 + ... + 6953.

It is an arithmetic number, because the mean of its divisors is an integer number (438480).

Almost surely, 2^7721865 is an apocalyptic number.

It is an amenable number.

7721865 is a deficient number, since it is larger than the sum of its proper divisors (6309495).

7721865 is a wasteful number, since it uses less digits than its factorization.

7721865 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1278 (or 1272 counting only the distinct ones).

The product of its digits is 23520, while the sum is 36.

The square root of 7721865 is about 2778.8243917168. The cubic root of 7721865 is about 197.6548163878.

The spelling of 7721865 in words is "seven million, seven hundred twenty-one thousand, eight hundred sixty-five".