27777657997 has 2 divisors, whose sum is σ = 27777657998. Its totient is φ = 27777657996.

The previous prime is 27777657967. The next prime is 27777658039. The reversal of 27777657997 is 79975677772.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 24194558116 + 3583099881 = 155546^2 + 59859^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-27777657997 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (27777657967) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 13888828998 + 13888828999.

It is an arithmetic number, because the mean of its divisors is an integer number (13888828999).

Almost surely, 2^27777657997 is an apocalyptic number.

It is an amenable number.

27777657997 is a deficient number, since it is larger than the sum of its proper divisors (1).

27777657997 is an equidigital number, since it uses as much as digits as its factorization.

27777657997 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 571774140, while the sum is 73.

The spelling of 27777657997 in words is "twenty-seven billion, seven hundred seventy-seven million, six hundred fifty-seven thousand, nine hundred ninety-seven".