216221818883021 has 16 divisors (see below), whose sum is σ = 251775264397824. Its totient is φ = 181834586628864.

The previous prime is 216221818882999. The next prime is 216221818883033. The reversal of 216221818883021 is 120388818122612.

It is a cyclic number.

It is not a de Polignac number, because 216221818883021 - 2⁶ = 216221818882957 is a prime.

It is a super-2 number, since 2×216221818883021² (a number of 29 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (53).

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (216221818583021) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 42110021 + ... + 46964853.

It is an arithmetic number, because the mean of its divisors is an integer number (15735954024864).

Almost surely, 2^{216221818883021} is an apocalyptic number.

It is an amenable number.

216221818883021 is a deficient number, since it is larger than the sum of its proper divisors (35553445514803).

216221818883021 is a wasteful number, since it uses less digits than its factorization.

216221818883021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4974940.

The product of its (nonzero) digits is 1179648, while the sum is 53.

The spelling of 216221818883021 in words is "two hundred sixteen trillion, two hundred twenty-one billion, eight hundred eighteen million, eight hundred eighty-three thousand, twenty-one".