216666135242 has 16 divisors (see below), whose sum is σ = 326143744872. Its totient is φ = 107952143040.

The previous prime is 216666135221. The next prime is 216666135293. The reversal of 216666135242 is 242531666612.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 199407795601 + 17258339641 = 446551^2 + 131371^2 .

It is a junction number, because it is equal to n+sod(n) for n = 216666135193 and 216666135202.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 591728 + ... + 885140.

Almost surely, 2^216666135242 is an apocalyptic number.

216666135242 is a deficient number, since it is larger than the sum of its proper divisors (109477609630).

216666135242 is a wasteful number, since it uses less digits than its factorization.

216666135242 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 294713.

The product of its digits is 622080, while the sum is 44.

The spelling of 216666135242 in words is "two hundred sixteen billion, six hundred sixty-six million, one hundred thirty-five thousand, two hundred forty-two".