6721609077 has 24 divisors (see below), whose sum is σ = 9756061848. Its totient is φ = 4459392000.

The previous prime is 6721609057. The next prime is 6721609091. The reversal of 6721609077 is 7709061276.

It can be written as a sum of positive squares in 4 ways, for example, as 1326853476 + 5394755601 = 36426^2 + 73449^2 .

It is a de Polignac number, because none of the positive numbers 2^k-6721609077 is a prime.

It is a super-3 number, since 3×6721609077³ (a number of 30 digits) contains 333 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6721609057) by changing a digit.

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 23 ways as a sum of consecutive naturals, for example, 3036223 + ... + 3038435.

It is an arithmetic number, because the mean of its divisors is an integer number (406502577).

Almost surely, 2^6721609077 is an apocalyptic number.

It is an amenable number.

6721609077 is a deficient number, since it is larger than the sum of its proper divisors (3034452771).

6721609077 is a wasteful number, since it uses less digits than its factorization.

6721609077 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3701 (or 3698 counting only the distinct ones).

The product of its (nonzero) digits is 222264, while the sum is 45.

The square root of 6721609077 is about 81985.4199050051. The cubic root of 6721609077 is about 1887.2281978224.

The spelling of 6721609077 in words is "six billion, seven hundred twenty-one million, six hundred nine thousand, seventy-seven".