7721856 has 48 divisors (see below), whose sum is σ = 22223760. Its totient is φ = 2573568.

The previous prime is 7721849. The next prime is 7721873. The reversal of 7721856 is 6581277.

It is a tau number, because it is divible by the number of its divisors (48).

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 Harshad number since it is a multiple of its sum of digits (36).

It is a self number, because there is not a number n which added to its sum of digits gives 7721856.

It is a congruent number.

It is an unprimeable number.

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 5 ways as a sum of consecutive naturals, for example, 2200 + ... + 4503.

It is an arithmetic number, because the mean of its divisors is an integer number (462995).

Almost surely, 2^7721856 is an apocalyptic number.

It is an amenable number.

7721856 is an abundant number, since it is smaller than the sum of its proper divisors (14501904).

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

7721856 is a wasteful number, since it uses less digits than its factorization.

7721856 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6723 (or 6708 counting only the distinct ones).

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

The square root of 7721856 is about 2778.8227723264. The cubic root of 7721856 is about 197.6547395975.

It can be divided in two parts, 772 and 1856, that added together give a triangular number (2628 = T₇₂).

The spelling of 7721856 in words is "seven million, seven hundred twenty-one thousand, eight hundred fifty-six".