26998271981 has 2 divisors, whose sum is σ = 26998271982. Its totient is φ = 26998271980.

The previous prime is 26998271957. The next prime is 26998272001. The reversal of 26998271981 is 18917289962.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 17649122500 + 9349149481 = 132850^2 + 96691^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-26998271981 is a prime.

It is a super-2 number, since 2×26998271981² (a number of 22 digits) contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (26998271381) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 13499135990 + 13499135991.

It is an arithmetic number, because the mean of its divisors is an integer number (13499135991).

Almost surely, 2^26998271981 is an apocalyptic number.

It is an amenable number.

26998271981 is a deficient number, since it is larger than the sum of its proper divisors (1).

26998271981 is an equidigital number, since it uses as much as digits as its factorization.

26998271981 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 7838208, while the sum is 62.

The spelling of 26998271981 in words is "twenty-six billion, nine hundred ninety-eight million, two hundred seventy-one thousand, nine hundred eighty-one".