27540507721 has 2 divisors, whose sum is σ = 27540507722. Its totient is φ = 27540507720.

The previous prime is 27540507679. The next prime is 27540507737. The reversal of 27540507721 is 12770504572.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 25765065225 + 1775442496 = 160515^2 + 42136^2 .

It is a cyclic number.

It is not a de Polignac number, because 27540507721 - 2⁹ = 27540507209 is a prime.

It is a super-2 number, since 2×27540507721² (a number of 22 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (27540507121) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 13770253860 + 13770253861.

It is an arithmetic number, because the mean of its divisors is an integer number (13770253861).

Almost surely, 2^27540507721 is an apocalyptic number.

It is an amenable number.

27540507721 is a deficient number, since it is larger than the sum of its proper divisors (1).

27540507721 is an equidigital number, since it uses as much as digits as its factorization.

27540507721 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 137200, while the sum is 40.

The spelling of 27540507721 in words is "twenty-seven billion, five hundred forty million, five hundred seven thousand, seven hundred twenty-one".