27660838921 has 2 divisors, whose sum is σ = 27660838922. Its totient is φ = 27660838920.

The previous prime is 27660838883. The next prime is 27660838949. The reversal of 27660838921 is 12983806672.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 22825166400 + 4835672521 = 151080^2 + 69539^2 .

It is a cyclic number.

It is not a de Polignac number, because 27660838921 - 2¹⁵ = 27660806153 is a prime.

It is a super-3 number, since 3×27660838921³ (a number of 32 digits) contains 333 as substring.

It is not a weakly prime, because it can be changed into another prime (27660832921) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 13830419460 + 13830419461.

It is an arithmetic number, because the mean of its divisors is an integer number (13830419461).

Almost surely, 2^27660838921 is an apocalyptic number.

It is an amenable number.

27660838921 is a deficient number, since it is larger than the sum of its proper divisors (1).

27660838921 is an equidigital number, since it uses as much as digits as its factorization.

27660838921 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1741824, while the sum is 52.

The spelling of 27660838921 in words is "twenty-seven billion, six hundred sixty million, eight hundred thirty-eight thousand, nine hundred twenty-one".