66565106202421 has 16 divisors (see below), whose sum is σ = 67022723893248. Its totient is φ = 66109381430400.

The previous prime is 66565106202409. The next prime is 66565106202521. The reversal of 66565106202421 is 12420260156566.

66565106202421 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a cyclic number.

It is not a de Polignac number, because 66565106202421 - 2¹⁷ = 66565106071349 is a prime.

It is a super-2 number, since 2×66565106202421² (a number of 28 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66565106202521) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 113808636 + ... + 114392026.

It is an arithmetic number, because the mean of its divisors is an integer number (4188920243328).

Almost surely, 2^{66565106202421} is an apocalyptic number.

It is an amenable number.

66565106202421 is a deficient number, since it is larger than the sum of its proper divisors (457617690827).

66565106202421 is a wasteful number, since it uses less digits than its factorization.

66565106202421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 585012.

The product of its (nonzero) digits is 1036800, while the sum is 46.

Adding to 66565106202421 its reverse (12420260156566), we get a palindrome (78985366358987).

The spelling of 66565106202421 in words is "sixty-six trillion, five hundred sixty-five billion, one hundred six million, two hundred two thousand, four hundred twenty-one".