26261981 has 2 divisors, whose sum is σ = 26261982. Its totient is φ = 26261980.

The previous prime is 26261951. The next prime is 26261987. The reversal of 26261981 is 18916262.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 18748900 + 7513081 = 4330^2 + 2741^2 .

It is a cyclic number.

It is not a de Polignac number, because 26261981 - 2¹⁰ = 26260957 is a prime.

It is a super-2 number, since 2×26261981² = 1379383292088722, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Chen 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 (26261987) by changing a digit.

It is a good prime.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 13130990 + 13130991.

It is an arithmetic number, because the mean of its divisors is an integer number (13130991).

Almost surely, 2^26261981 is an apocalyptic number.

It is an amenable number.

26261981 is a deficient number, since it is larger than the sum of its proper divisors (1).

26261981 is an equidigital number, since it uses as much as digits as its factorization.

26261981 is an evil number, because the sum of its binary digits is even.

The product of its digits is 10368, while the sum is 35.

The square root of 26261981 is about 5124.6444754734. The cubic root of 26261981 is about 297.2413060808.

The spelling of 26261981 in words is "twenty-six million, two hundred sixty-one thousand, nine hundred eighty-one".