21173220606481 has 8 divisors (see below), whose sum is σ = 21704425008840. Its totient is φ = 20648534049792.

The previous prime is 21173220606403. The next prime is 21173220606511. The reversal of 21173220606481 is 18460602237112.

It can be written as a sum of positive squares in 4 ways, for example, as 5357447227456 + 15815773379025 = 2314616^2 + 3976905^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21173220606481 - 2⁷ = 21173220606353 is a prime.

It is a super-2 number, since 2×21173220606481² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21173280606481) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1629454840 + ... + 1629467833.

It is an arithmetic number, because the mean of its divisors is an integer number (2713053126105).

Almost surely, 2^{21173220606481} is an apocalyptic number.

It is an amenable number.

21173220606481 is a deficient number, since it is larger than the sum of its proper divisors (531204402359).

21173220606481 is an equidigital number, since it uses as much as digits as its factorization.

21173220606481 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3258922835.

The product of its (nonzero) digits is 193536, while the sum is 43.

The spelling of 21173220606481 in words is "twenty-one trillion, one hundred seventy-three billion, two hundred twenty million, six hundred six thousand, four hundred eighty-one".