221012905 has 16 divisors (see below), whose sum is σ = 272219904. Its totient is φ = 172166400.

The previous prime is 221012881. The next prime is 221012917. The reversal of 221012905 is 509210122.

221012905 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 221012905 - 2⁷ = 221012777 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 77505 + ... + 80305.

It is an arithmetic number, because the mean of its divisors is an integer number (17013744).

Almost surely, 2^221012905 is an apocalyptic number.

It is an amenable number.

221012905 is a deficient number, since it is larger than the sum of its proper divisors (51206999).

221012905 is a wasteful number, since it uses less digits than its factorization.

221012905 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3216.

The product of its (nonzero) digits is 360, while the sum is 22.

The square root of 221012905 is about 14866.5027831027. The cubic root of 221012905 is about 604.6061275324.

The spelling of 221012905 in words is "two hundred twenty-one million, twelve thousand, nine hundred five".