27123781973 has 2 divisors, whose sum is σ = 27123781974. Its totient is φ = 27123781972.

The previous prime is 27123781957. The next prime is 27123781981. The reversal of 27123781973 is 37918732172.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 15046211569 + 12077570404 = 122663^2 + 109898^2 .

It is a cyclic number.

It is not a de Polignac number, because 27123781973 - 2⁴ = 27123781957 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (27123786973) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 13561890986 + 13561890987.

It is an arithmetic number, because the mean of its divisors is an integer number (13561890987).

Almost surely, 2^27123781973 is an apocalyptic number.

It is an amenable number.

27123781973 is a deficient number, since it is larger than the sum of its proper divisors (1).

27123781973 is an equidigital number, since it uses as much as digits as its factorization.

27123781973 is an evil number, because the sum of its binary digits is even.

The product of its digits is 889056, while the sum is 50.

The spelling of 27123781973 in words is "twenty-seven billion, one hundred twenty-three million, seven hundred eighty-one thousand, nine hundred seventy-three".