666426210305 has 4 divisors (see below), whose sum is σ = 799711452372. Its totient is φ = 533140968240.

The previous prime is 666426210293. The next prime is 666426210343. The reversal of 666426210305 is 503012624666.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 311399713024 + 355026497281 = 558032^2 + 595841^2 .

It is not a de Polignac number, because 666426210305 - 2²⁴ = 666409433089 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 66642621026 + ... + 66642621035.

It is an arithmetic number, because the mean of its divisors is an integer number (199927863093).

Almost surely, 2^666426210305 is an apocalyptic number.

It is an amenable number.

666426210305 is a deficient number, since it is larger than the sum of its proper divisors (133285242067).

666426210305 is a wasteful number, since it uses less digits than its factorization.

666426210305 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 133285242066.

The product of its (nonzero) digits is 311040, while the sum is 41.

The spelling of 666426210305 in words is "six hundred sixty-six billion, four hundred twenty-six million, two hundred ten thousand, three hundred five".