21520533105 has 12 divisors (see below), whose sum is σ = 37302257460. Its totient is φ = 11477617632.

The previous prime is 21520533077. The next prime is 21520533107. The reversal of 21520533105 is 50133502512.

It is a happy number.

21520533105 is a `hidden beast` number, since 2 + 1 + 5 + 20 + 533 + 105 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 3801462336 + 17719070769 = 61656^2 + 133113^2 .

It is not a de Polignac number, because 21520533105 - 2¹³ = 21520524913 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21520533107) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 239116990 + ... + 239117079.

It is an arithmetic number, because the mean of its divisors is an integer number (3108521455).

Almost surely, 2^21520533105 is an apocalyptic number.

It is an amenable number.

21520533105 is a deficient number, since it is larger than the sum of its proper divisors (15781724355).

21520533105 is a wasteful number, since it uses less digits than its factorization.

21520533105 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 478234080 (or 478234077 counting only the distinct ones).

The product of its (nonzero) digits is 4500, while the sum is 27.

The spelling of 21520533105 in words is "twenty-one billion, five hundred twenty million, five hundred thirty-three thousand, one hundred five".