27868629721 has 9 divisors (see below), whose sum is σ = 28093957983. Its totient is φ = 27645098400.

The previous prime is 27868629713. The next prime is 27868629739. The reversal of 27868629721 is 12792686872.

It is a happy number.

The square root of 27868629721 is 166939.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 46389721 + 27822240000 = 6811^2 + 166800^2 .

It is not a de Polignac number, because 27868629721 - 2³ = 27868629713 is a prime.

It is a super-3 number, since 3×27868629721³ (a number of 32 digits) contains 333 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (27868629421) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 23203921 + ... + 23205121.

It is an arithmetic number, because the mean of its divisors is an integer number (3121550887).

Almost surely, 2^27868629721 is an apocalyptic number.

27868629721 is the 166939-th square number.

27868629721 is the 83470-th centered octagonal number.

It is an amenable number.

27868629721 is a deficient number, since it is larger than the sum of its proper divisors (225328262).

27868629721 is an frugal number, since it uses more digits than its factorization.

27868629721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2680 (or 1340 counting only the distinct ones).

The product of its digits is 8128512, while the sum is 58.

The spelling of 27868629721 in words is "twenty-seven billion, eight hundred sixty-eight million, six hundred twenty-nine thousand, seven hundred twenty-one".