221994181920 has 192 divisors, whose sum is σ = 799468379136. Its totient is φ = 50723159040.

The previous prime is 221994181907. The next prime is 221994181951. The reversal of 221994181920 is 29181499122.

It is a happy number.

221994181920 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a super-3 number, since 3×221994181920³ (a number of 35 digits) contains 333 as substring.

It is a Harshad number since it is a multiple of its sum of digits (48).

It is a self number, because there is not a number n which added to its sum of digits gives 221994181920.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 10697955 + ... + 10718685.

It is an arithmetic number, because the mean of its divisors is an integer number (4163897808).

Almost surely, 2^221994181920 is an apocalyptic number.

221994181920 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 221994181920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (399734189568).

221994181920 is an abundant number, since it is smaller than the sum of its proper divisors (577474197216).

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

221994181920 is a wasteful number, since it uses less digits than its factorization.

221994181920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23943 (or 23935 counting only the distinct ones).

The product of its (nonzero) digits is 186624, while the sum is 48.

The spelling of 221994181920 in words is "two hundred twenty-one billion, nine hundred ninety-four million, one hundred eighty-one thousand, nine hundred twenty".