7667616521 has 4 divisors (see below), whose sum is σ = 7746664212. Its totient is φ = 7588568832.

The previous prime is 7667616373. The next prime is 7667616527. The reversal of 7667616521 is 1256167667.

7667616521 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 2482032400 + 5185584121 = 49820^2 + 72011^2 .

It is a cyclic number.

It is not a de Polignac number, because 7667616521 - 2¹⁰ = 7667615497 is a prime.

It is a super-2 number, since 2×7667616521² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (7667616527) 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 3 ways as a sum of consecutive naturals, for example, 39523700 + ... + 39523893.

It is an arithmetic number, because the mean of its divisors is an integer number (1936666053).

Almost surely, 2^7667616521 is an apocalyptic number.

It is an amenable number.

7667616521 is a deficient number, since it is larger than the sum of its proper divisors (79047691).

7667616521 is an equidigital number, since it uses as much as digits as its factorization.

7667616521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 79047690.

The product of its digits is 635040, while the sum is 47.

The square root of 7667616521 is about 87564.9274595714. The cubic root of 7667616521 is about 1971.9086624205.

The spelling of 7667616521 in words is "seven billion, six hundred sixty-seven million, six hundred sixteen thousand, five hundred twenty-one".