216571661816628 has 48 divisors (see below), whose sum is σ = 513620575623680. Its totient is φ = 71006751619200.

The previous prime is 216571661816599. The next prime is 216571661816651. The reversal of 216571661816628 is 826618166175612.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 177201858 + ... + 178419846.

Almost surely, 2^{216571661816628} is an apocalyptic number.

It is an amenable number.

216571661816628 is an abundant number, since it is smaller than the sum of its proper divisors (297048913807052).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

216571661816628 is a wasteful number, since it uses less digits than its factorization.

216571661816628 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1460968 (or 1460966 counting only the distinct ones).

The product of its digits is 69672960, while the sum is 66.

The spelling of 216571661816628 in words is "two hundred sixteen trillion, five hundred seventy-one billion, six hundred sixty-one million, eight hundred sixteen thousand, six hundred twenty-eight".