26198106581 has 16 divisors (see below), whose sum is σ = 28621506816. Its totient is φ = 23883565056.

The previous prime is 26198106559. The next prime is 26198106589. The reversal of 26198106581 is 18560189162.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 26198106581 - 2¹⁴ = 26198090197 is a prime.

It is a super-2 number, since 2×26198106581² (a number of 22 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (47).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (26198106589) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 91511 + ... + 246516.

It is an arithmetic number, because the mean of its divisors is an integer number (1788844176).

Almost surely, 2^26198106581 is an apocalyptic number.

It is an amenable number.

26198106581 is a deficient number, since it is larger than the sum of its proper divisors (2423400235).

26198106581 is a wasteful number, since it uses less digits than its factorization.

26198106581 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 338188.

The product of its (nonzero) digits is 207360, while the sum is 47.

The spelling of 26198106581 in words is "twenty-six billion, one hundred ninety-eight million, one hundred six thousand, five hundred eighty-one".