221766928920 has 640 divisors, whose sum is σ = 796938912000. Its totient is φ = 55212917760.

The previous prime is 221766928919. The next prime is 221766928969. The reversal of 221766928920 is 29829667122.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is an unprimeable number.

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 159 ways as a sum of consecutive naturals, for example, 529276471 + ... + 529276889.

It is an arithmetic number, because the mean of its divisors is an integer number (1245217050).

Almost surely, 2^221766928920 is an apocalyptic number.

221766928920 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 221766928920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (398469456000).

221766928920 is an abundant number, since it is smaller than the sum of its proper divisors (575171983080).

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

221766928920 is a wasteful number, since it uses less digits than its factorization.

221766928920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 645 (or 632 counting only the distinct ones).

The product of its (nonzero) digits is 2612736, while the sum is 54.

The spelling of 221766928920 in words is "two hundred twenty-one billion, seven hundred sixty-six million, nine hundred twenty-eight thousand, nine hundred twenty".