26021581 has 2 divisors, whose sum is σ = 26021582. Its totient is φ = 26021580.

The previous prime is 26021557. The next prime is 26021591. The reversal of 26021581 is 18512062.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 24900100 + 1121481 = 4990^2 + 1059^2 .

It is a cyclic number.

It is not a de Polignac number, because 26021581 - 2⁵ = 26021549 is a prime.

It is a super-2 number, since 2×26021581² = 1354245355479122, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (26021521) 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, 13010790 + 13010791.

It is an arithmetic number, because the mean of its divisors is an integer number (13010791).

Almost surely, 2^26021581 is an apocalyptic number.

It is an amenable number.

26021581 is a deficient number, since it is larger than the sum of its proper divisors (1).

26021581 is an equidigital number, since it uses as much as digits as its factorization.

26021581 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 960, while the sum is 25.

The square root of 26021581 is about 5101.1352658011. The cubic root of 26021581 is about 296.3315503621.

The spelling of 26021581 in words is "twenty-six million, twenty-one thousand, five hundred eighty-one".