26531500221 has 24 divisors (see below), whose sum is σ = 38742267096. Its totient is φ = 17494646400.

The previous prime is 26531500217. The next prime is 26531500223. The reversal of 26531500221 is 12200513562.

It is a happy number.

26531500221 is a `hidden beast` number, since 2 + 653 + 1 + 5 + 0 + 0 + 2 + 2 + 1 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 433097721 + 26098402500 = 20811^2 + 161550^2 .

It is not a de Polignac number, because 26531500221 - 2² = 26531500217 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (26531500223) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 906411 + ... + 935223.

It is an arithmetic number, because the mean of its divisors is an integer number (1614261129).

Almost surely, 2^26531500221 is an apocalyptic number.

It is an amenable number.

26531500221 is a deficient number, since it is larger than the sum of its proper divisors (12210766875).

26531500221 is a wasteful number, since it uses less digits than its factorization.

26531500221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 29933 (or 29930 counting only the distinct ones).

The product of its (nonzero) digits is 3600, while the sum is 27.

The spelling of 26531500221 in words is "twenty-six billion, five hundred thirty-one million, five hundred thousand, two hundred twenty-one".