26155981 has 2 divisors, whose sum is σ = 26155982. Its totient is φ = 26155980.

The previous prime is 26155949. The next prime is 26156021. The reversal of 26155981 is 18955162.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 25593481 + 562500 = 5059^2 + 750^2 .

It is a cyclic number.

It is not a de Polignac number, because 26155981 - 2⁵ = 26155949 is a prime.

It is a super-2 number, since 2×26155981² = 1368270684144722, 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 26155981.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (26155901) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 13077990 + 13077991.

It is an arithmetic number, because the mean of its divisors is an integer number (13077991).

Almost surely, 2^26155981 is an apocalyptic number.

It is an amenable number.

26155981 is a deficient number, since it is larger than the sum of its proper divisors (1).

26155981 is an equidigital number, since it uses as much as digits as its factorization.

26155981 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 21600, while the sum is 37.

The square root of 26155981 is about 5114.2918375861. The cubic root of 26155981 is about 296.8408531141.

The spelling of 26155981 in words is "twenty-six million, one hundred fifty-five thousand, nine hundred eighty-one".