21558755241 has 27 divisors (see below), whose sum is σ = 33091460311. Its totient is φ = 13522363584.

The previous prime is 21558755171. The next prime is 21558755261. The reversal of 21558755241 is 14255785512.

It is a happy number.

The square root of 21558755241 is 146829.

It is a perfect power (a square), and thus also a powerful number.

21558755241 is a `hidden beast` number, since 2 + 1 + 5 + 58 + 7 + 552 + 41 = 666.

It can be written as a sum of positive squares in only one way, i.e., 16784498025 + 4774257216 = 129555^2 + 69096^2 .

It is not a de Polignac number, because 21558755241 - 2⁹ = 21558754729 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21558755261) by changing a digit.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 7486840 + ... + 7489718.

Almost surely, 2^21558755241 is an apocalyptic number.

21558755241 is the 146829-th square number.

21558755241 is the 73415-th centered octagonal number.

It is an amenable number.

21558755241 is a deficient number, since it is larger than the sum of its proper divisors (11532705070).

21558755241 is an frugal number, since it uses more digits than its factorization.

21558755241 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5798 (or 2899 counting only the distinct ones).

The product of its digits is 560000, while the sum is 45.

The spelling of 21558755241 in words is "twenty-one billion, five hundred fifty-eight million, seven hundred fifty-five thousand, two hundred forty-one".