21520478068801 has 4 divisors (see below), whose sum is σ = 21521297516992. Its totient is φ = 21519658620612.

The previous prime is 21520478068769. The next prime is 21520478068819. The reversal of 21520478068801 is 10886087402512.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21520478068801 - 2⁵ = 21520478068769 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21520478068861) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 409684701 + ... + 409737226.

It is an arithmetic number, because the mean of its divisors is an integer number (5380324379248).

Almost surely, 2^{21520478068801} is an apocalyptic number.

It is an amenable number.

21520478068801 is a deficient number, since it is larger than the sum of its proper divisors (819448191).

21520478068801 is an equidigital number, since it uses as much as digits as its factorization.

21520478068801 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 819448190.

The product of its (nonzero) digits is 1720320, while the sum is 52.

The spelling of 21520478068801 in words is "twenty-one trillion, five hundred twenty billion, four hundred seventy-eight million, sixty-eight thousand, eight hundred one".