66441343421 has 4 divisors (see below), whose sum is σ = 66443113344. Its totient is φ = 66439573500.

The previous prime is 66441343349. The next prime is 66441343427. The reversal of 66441343421 is 12434314466.

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 66441343421 - 2¹⁰ = 66441342397 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66441343427) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 827405 + ... + 904146.

It is an arithmetic number, because the mean of its divisors is an integer number (16610778336).

Almost surely, 2^66441343421 is an apocalyptic number.

It is an amenable number.

66441343421 is a deficient number, since it is larger than the sum of its proper divisors (1769923).

66441343421 is a wasteful number, since it uses less digits than its factorization.

66441343421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1769922.

The product of its digits is 165888, while the sum is 38.

Adding to 66441343421 its reverse (12434314466), we get a palindrome (78875657887).

The spelling of 66441343421 in words is "sixty-six billion, four hundred forty-one million, three hundred forty-three thousand, four hundred twenty-one".