221997978072 has 256 divisors, whose sum is σ = 669985344000. Its totient is φ = 67704159744.

The previous prime is 221997978031. The next prime is 221997978073. The reversal of 221997978072 is 270879799122.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221997978073) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 222665478 + ... + 222666474.

It is an arithmetic number, because the mean of its divisors is an integer number (2617130250).

Almost surely, 2^221997978072 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 221997978072, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (334992672000).

221997978072 is an abundant number, since it is smaller than the sum of its proper divisors (447987365928).

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

221997978072 is a wasteful number, since it uses less digits than its factorization.

221997978072 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1647 (or 1637 counting only the distinct ones).

The product of its (nonzero) digits is 16003008, while the sum is 63.

The spelling of 221997978072 in words is "two hundred twenty-one billion, nine hundred ninety-seven million, nine hundred seventy-eight thousand, seventy-two".