221008745 has 8 divisors (see below), whose sum is σ = 265626816. Its totient is φ = 176529456.

The previous prime is 221008699. The next prime is 221008747. The reversal of 221008745 is 547800122.

221008745 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

It is a cyclic number.

It is not a de Polignac number, because 221008745 - 2¹⁶ = 220943209 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (221008747) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 31157 + ... + 37586.

It is an arithmetic number, because the mean of its divisors is an integer number (33203352).

Almost surely, 2^221008745 is an apocalyptic number.

It is an amenable number.

221008745 is a deficient number, since it is larger than the sum of its proper divisors (44618071).

221008745 is an equidigital number, since it uses as much as digits as its factorization.

221008745 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 69391.

The product of its (nonzero) digits is 4480, while the sum is 29.

The square root of 221008745 is about 14866.3628705881. The cubic root of 221008745 is about 604.6023341230.

Adding to 221008745 its reverse (547800122), we get a palindrome (768808867).

The spelling of 221008745 in words is "two hundred twenty-one million, eight thousand, seven hundred forty-five".