666421472099 has 24 divisors (see below), whose sum is σ = 740782506240. Its totient is φ = 598252110192.

The previous prime is 666421472083. The next prime is 666421472141. The reversal of 666421472099 is 990274124666.

666421472099 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 666421472099 - 2⁴ = 666421472083 is a prime.

It is a Smith number, since the sum of its digits (56) coincides with the sum of the digits of its prime factors.

It is not an unprimeable number, because it can be changed into a prime (666421472039) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 513362 + ... + 1263480.

It is an arithmetic number, because the mean of its divisors is an integer number (30865937760).

Almost surely, 2^666421472099 is an apocalyptic number.

666421472099 is a deficient number, since it is larger than the sum of its proper divisors (74361034141).

666421472099 is a wasteful number, since it uses less digits than its factorization.

666421472099 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 750287 (or 750268 counting only the distinct ones).

The product of its (nonzero) digits is 7838208, while the sum is 56.

The spelling of 666421472099 in words is "six hundred sixty-six billion, four hundred twenty-one million, four hundred seventy-two thousand, ninety-nine".