7021655666220 has 144 divisors (see below), whose sum is σ = 21384802317312. Its totient is φ = 1720656288000.

The previous prime is 7021655666219. The next prime is 7021655666257. The reversal of 7021655666220 is 226665561207.

It is a super-4 number, since 4×7021655666220⁴ (a number of 52 digits) contains 4444 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 7021655666220.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 708595 + ... + 3813845.

It is an arithmetic number, because the mean of its divisors is an integer number (148505571648).

Almost surely, 2^{7021655666220} is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 7021655666220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (10692401158656).

7021655666220 is an abundant number, since it is smaller than the sum of its proper divisors (14363146651092).

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

7021655666220 is a wasteful number, since it uses less digits than its factorization.

7021655666220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3105512 (or 3105497 counting only the distinct ones).

The product of its (nonzero) digits is 1814400, while the sum is 48.

The spelling of 7021655666220 in words is "seven trillion, twenty-one billion, six hundred fifty-five million, six hundred sixty-six thousand, two hundred twenty".