667216421787 has 8 divisors (see below), whose sum is σ = 941952595536. Its totient is φ = 418645597952.

The previous prime is 667216421737. The next prime is 667216421797. The reversal of 667216421787 is 787124612766.

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 667216421787 - 2²⁰ = 667215373211 is a prime.

It is not an unprimeable number, because it can be changed into a prime (667216421737) 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, 6541337418 + ... + 6541337519.

It is an arithmetic number, because the mean of its divisors is an integer number (117744074442).

Almost surely, 2^667216421787 is an apocalyptic number.

667216421787 is a deficient number, since it is larger than the sum of its proper divisors (274736173749).

667216421787 is a wasteful number, since it uses less digits than its factorization.

667216421787 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13082674957.

The product of its digits is 9483264, while the sum is 57.

The spelling of 667216421787 in words is "six hundred sixty-seven billion, two hundred sixteen million, four hundred twenty-one thousand, seven hundred eighty-seven".