221386652928 has 288 divisors, whose sum is σ = 748992894720. Its totient is φ = 63186739200.

The previous prime is 221386652917. The next prime is 221386652933. The reversal of 221386652928 is 829256683122.

221386652928 is a `hidden beast` number, since 2 + 2 + 1 + 38 + 66 + 529 + 28 = 666.

It is a tau number, because it is divible by the number of its divisors (288).

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 31 ways as a sum of consecutive naturals, for example, 62945826 + ... + 62949342.

Almost surely, 2^221386652928 is an apocalyptic number.

221386652928 is a gapful number since it is divisible by the number (28) 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 221386652928, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (374496447360).

221386652928 is an abundant number, since it is smaller than the sum of its proper divisors (527606241792).

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

221386652928 is a wasteful number, since it uses less digits than its factorization.

221386652928 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4850 (or 4830 counting only the distinct ones).

The product of its digits is 4976640, while the sum is 54.

The spelling of 221386652928 in words is "two hundred twenty-one billion, three hundred eighty-six million, six hundred fifty-two thousand, nine hundred twenty-eight".