26173981 has 2 divisors, whose sum is σ = 26173982. Its totient is φ = 26173980.

The previous prime is 26173943. The next prime is 26174003. The reversal of 26173981 is 18937162.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 24651225 + 1522756 = 4965^2 + 1234^2 .

It is a cyclic number.

It is not a de Polignac number, because 26173981 - 2¹⁷ = 26042909 is a prime.

It is a super-2 number, since 2×26173981² = 1370154562776722, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 26173981.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (26173181) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 13086990 + 13086991.

It is an arithmetic number, because the mean of its divisors is an integer number (13086991).

Almost surely, 2^26173981 is an apocalyptic number.

It is an amenable number.

26173981 is a deficient number, since it is larger than the sum of its proper divisors (1).

26173981 is an equidigital number, since it uses as much as digits as its factorization.

26173981 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 18144, while the sum is 37.

The square root of 26173981 is about 5116.0513093596. The cubic root of 26173981 is about 296.9089307257.

The spelling of 26173981 in words is "twenty-six million, one hundred seventy-three thousand, nine hundred eighty-one".