221789705 has 8 divisors (see below), whose sum is σ = 272639304. Its totient is φ = 173104000.

The previous prime is 221789677. The next prime is 221789719. The reversal of 221789705 is 507987122.

It can be written as a sum of positive squares in 4 ways, for example, as 1207801 + 220581904 = 1099^2 + 14852^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a de Polignac number, because none of the positive numbers 2^k-221789705 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (41).

It is a Duffinian number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 540746 + ... + 541155.

It is an arithmetic number, because the mean of its divisors is an integer number (34079913).

Almost surely, 2^221789705 is an apocalyptic number.

It is an amenable number.

221789705 is a deficient number, since it is larger than the sum of its proper divisors (50849599).

221789705 is a wasteful number, since it uses less digits than its factorization.

221789705 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1081947.

The product of its (nonzero) digits is 70560, while the sum is 41.

The square root of 221789705 is about 14892.6057155892. The cubic root of 221789705 is about 605.3136410776.

The spelling of 221789705 in words is "two hundred twenty-one million, seven hundred eighty-nine thousand, seven hundred five".