7721065686 has 16 divisors (see below), whose sum is σ = 15445743984. Its totient is φ = 2573086464.

The previous prime is 7721065669. The next prime is 7721065691. The reversal of 7721065686 is 6865601277.

It is a super-2 number, since 2×7721065686² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

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, 122335 + ... + 174378.

It is an arithmetic number, because the mean of its divisors is an integer number (965358999).

Almost surely, 2^7721065686 is an apocalyptic number.

7721065686 is an abundant number, since it is smaller than the sum of its proper divisors (7724678298).

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

7721065686 is a wasteful number, since it uses less digits than its factorization.

7721065686 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 301055.

The product of its (nonzero) digits is 846720, while the sum is 48.

The square root of 7721065686 is about 87869.5947754398. The cubic root of 7721065686 is about 1976.4799619980.

The spelling of 7721065686 in words is "seven billion, seven hundred twenty-one million, sixty-five thousand, six hundred eighty-six".