216665021652 has 48 divisors (see below), whose sum is σ = 519676368960. Its totient is φ = 70207333632.

The previous prime is 216665021609. The next prime is 216665021687. The reversal of 216665021652 is 256120566612.

It is a happy number.

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, 285163 + ... + 717389.

It is an arithmetic number, because the mean of its divisors is an integer number (10826591020).

Almost surely, 2^216665021652 is an apocalyptic number.

It is an amenable number.

216665021652 is an abundant number, since it is smaller than the sum of its proper divisors (303011347308).

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

216665021652 is a wasteful number, since it uses less digits than its factorization.

216665021652 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 433400 (or 433398 counting only the distinct ones).

The product of its (nonzero) digits is 259200, while the sum is 42.

The spelling of 216665021652 in words is "two hundred sixteen billion, six hundred sixty-five million, twenty-one thousand, six hundred fifty-two".