27731320081921 has 8 divisors (see below), whose sum is σ = 28043968516200. Its totient is φ = 27418695216000.

The previous prime is 27731320081901. The next prime is 27731320081931. The reversal of 27731320081921 is 12918002313772.

It can be written as a sum of positive squares in 4 ways, for example, as 3343920592321 + 24387399489600 = 1828639^2 + 4938360^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 27731320081921 - 2²³ = 27731311693313 is a prime.

It is a super-2 number, since 2×27731320081921² (a number of 28 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (27731320081901) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3520206 + ... + 8237383.

It is an arithmetic number, because the mean of its divisors is an integer number (3505496064525).

Almost surely, 2^{27731320081921} is an apocalyptic number.

It is an amenable number.

27731320081921 is a deficient number, since it is larger than the sum of its proper divisors (312648434279).

27731320081921 is a wasteful number, since it uses less digits than its factorization.

27731320081921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11784179.

The product of its (nonzero) digits is 254016, while the sum is 46.

The spelling of 27731320081921 in words is "twenty-seven trillion, seven hundred thirty-one billion, three hundred twenty million, eighty-one thousand, nine hundred twenty-one".