26401171221 has 12 divisors (see below), whose sum is σ = 38137455148. Its totient is φ = 17599659264.

The previous prime is 26401171211. The next prime is 26401171229. The reversal of 26401171221 is 12217110462.

26401171221 is a `hidden beast` number, since 2 + 640 + 1 + 1 + 7 + 12 + 2 + 1 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 2321890596 + 24079280625 = 48186^2 + 155175^2 .

It is not a de Polignac number, because 26401171221 - 2⁹ = 26401170709 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (26401171229) 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 11 ways as a sum of consecutive naturals, for example, 70821 + ... + 240453.

Almost surely, 2^26401171221 is an apocalyptic number.

It is an amenable number.

26401171221 is a deficient number, since it is larger than the sum of its proper divisors (11736283927).

26401171221 is a wasteful number, since it uses less digits than its factorization.

26401171221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 186932 (or 186929 counting only the distinct ones).

The product of its (nonzero) digits is 1344, while the sum is 27.

Adding to 26401171221 its reverse (12217110462), we get a palindrome (38618281683).

The spelling of 26401171221 in words is "twenty-six billion, four hundred one million, one hundred seventy-one thousand, two hundred twenty-one".