216456400666 has 8 divisors (see below), whose sum is σ = 354201382944. Its totient is φ = 98389273020.

The previous prime is 216456400609. The next prime is 216456400729. The reversal of 216456400666 is 666004654612.

It is a sphenic number, since it is the product of 3 distinct primes.

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, 4919463630 + ... + 4919463673.

It is an arithmetic number, because the mean of its divisors is an integer number (44275172868).

Almost surely, 2^216456400666 is an apocalyptic number.

216456400666 is a deficient number, since it is larger than the sum of its proper divisors (137744982278).

216456400666 is a wasteful number, since it uses less digits than its factorization.

216456400666 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9838927316.

The product of its (nonzero) digits is 1244160, while the sum is 46.

The spelling of 216456400666 in words is "two hundred sixteen billion, four hundred fifty-six million, four hundred thousand, six hundred sixty-six".