21520521330511 has 32 divisors (see below), whose sum is σ = 25853231416320. Its totient is φ = 17514228416256.

The previous prime is 21520521330479. The next prime is 21520521330521. The reversal of 21520521330511 is 11503312502512.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 21520521330511 - 2⁵ = 21520521330479 is a prime.

It is a super-2 number, since 2×21520521330511² (a number of 27 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21520521330521) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 585749380 + ... + 585786118.

It is an arithmetic number, because the mean of its divisors is an integer number (807913481760).

Almost surely, 2^{21520521330511} is an apocalyptic number.

21520521330511 is a deficient number, since it is larger than the sum of its proper divisors (4332710085809).

21520521330511 is a wasteful number, since it uses less digits than its factorization.

21520521330511 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 63463.

The product of its (nonzero) digits is 9000, while the sum is 31.

The spelling of 21520521330511 in words is "twenty-one trillion, five hundred twenty billion, five hundred twenty-one million, three hundred thirty thousand, five hundred eleven".