26971981 has 2 divisors, whose sum is σ = 26971982. Its totient is φ = 26971980.

The previous prime is 26971951. The next prime is 26971993. The reversal of 26971981 is 18917962.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 15642025 + 11329956 = 3955^2 + 3366^2 .

It is a cyclic number.

It is not a de Polignac number, because 26971981 - 2¹³ = 26963789 is a prime.

It is a super-2 number, since 2×26971981² = 1454975518128722, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (26971951) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 13485990 + 13485991.

It is an arithmetic number, because the mean of its divisors is an integer number (13485991).

Almost surely, 2^26971981 is an apocalyptic number.

It is an amenable number.

26971981 is a deficient number, since it is larger than the sum of its proper divisors (1).

26971981 is an equidigital number, since it uses as much as digits as its factorization.

26971981 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 54432, while the sum is 43.

The square root of 26971981 is about 5193.4555933405. The cubic root of 26971981 is about 299.8961900084.

The spelling of 26971981 in words is "twenty-six million, nine hundred seventy-one thousand, nine hundred eighty-one".