27661474397 has 2 divisors, whose sum is σ = 27661474398. Its totient is φ = 27661474396.

The previous prime is 27661474271. The next prime is 27661474439. The reversal of 27661474397 is 79347416672.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 16541560996 + 11119913401 = 128614^2 + 105451^2 .

It is a cyclic number.

It is not a de Polignac number, because 27661474397 - 2¹⁶ = 27661408861 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (27661474597) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 13830737198 + 13830737199.

It is an arithmetic number, because the mean of its divisors is an integer number (13830737199).

Almost surely, 2^27661474397 is an apocalyptic number.

It is an amenable number.

27661474397 is a deficient number, since it is larger than the sum of its proper divisors (1).

27661474397 is an equidigital number, since it uses as much as digits as its factorization.

27661474397 is an evil number, because the sum of its binary digits is even.

The product of its digits is 10668672, while the sum is 56.

The spelling of 27661474397 in words is "twenty-seven billion, six hundred sixty-one million, four hundred seventy-four thousand, three hundred ninety-seven".