105243655221 has 24 divisors (see below), whose sum is σ = 153116736344. Its totient is φ = 69656371200.

The previous prime is 105243655219. The next prime is 105243655249. The reversal of 105243655221 is 122556342501.

105243655221 is a `hidden beast` number, since 1 + 0 + 52 + 4 + 36 + 552 + 21 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 8628366321 + 96615288900 = 92889^2 + 310830^2 .

It is not a de Polignac number, because 105243655221 - 2¹ = 105243655219 is a prime.

It is a super-3 number, since 3×105243655221³ (a number of 34 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a hoax number, since the sum of its digits (36) coincides with the sum of the digits of its distinct prime factors.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (105243655271) 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, 1666005 + ... + 1728021.

Almost surely, 2^105243655221 is an apocalyptic number.

It is an amenable number.

105243655221 is a deficient number, since it is larger than the sum of its proper divisors (47873081123).

105243655221 is a wasteful number, since it uses less digits than its factorization.

105243655221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 63381 (or 63378 counting only the distinct ones).

The product of its (nonzero) digits is 72000, while the sum is 36.

Adding to 105243655221 its reverse (122556342501), we get a palindrome (227799997722).

The spelling of 105243655221 in words is "one hundred five billion, two hundred forty-three million, six hundred fifty-five thousand, two hundred twenty-one".