221662211672 has 128 divisors (see below), whose sum is σ = 479856960000. Its totient is φ = 95007728640.

The previous prime is 221662211623. The next prime is 221662211677. The reversal of 221662211672 is 276112266122.

221662211672 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221662211677) by changing a digit.

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, 67189079 + ... + 67192377.

It is an arithmetic number, because the mean of its divisors is an integer number (3748882500).

Almost surely, 2^221662211672 is an apocalyptic number.

221662211672 is a gapful number since it is divisible by the number (22) 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 221662211672, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (239928480000).

221662211672 is an abundant number, since it is smaller than the sum of its proper divisors (258194748328).

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

221662211672 is a wasteful number, since it uses less digits than its factorization.

221662211672 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3801 (or 3797 counting only the distinct ones).

The product of its digits is 48384, while the sum is 38.

Adding to 221662211672 its reverse (276112266122), we get a palindrome (497774477794).

It can be divided in two parts, 221662 and 211672, that added together give a palindrome (433334).

The spelling of 221662211672 in words is "two hundred twenty-one billion, six hundred sixty-two million, two hundred eleven thousand, six hundred seventy-two".