221312585 has 16 divisors (see below), whose sum is σ = 286348944. Its totient is φ = 163233792.

The previous prime is 221312573. The next prime is 221312593. The reversal of 221312585 is 585213122.

221312585 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 8 ways, for example, as 760384 + 220552201 = 872^2 + 14851^2 .

It is a cyclic number.

It is not a de Polignac number, because 221312585 - 2¹⁰ = 221311561 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, 73469 + ... + 76421.

It is an arithmetic number, because the mean of its divisors is an integer number (17896809).

Almost surely, 2^221312585 is an apocalyptic number.

It is an amenable number.

221312585 is a deficient number, since it is larger than the sum of its proper divisors (65036359).

221312585 is a wasteful number, since it uses less digits than its factorization.

221312585 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4124.

The product of its digits is 4800, while the sum is 29.

The square root of 221312585 is about 14876.5784036518. The cubic root of 221312585 is about 604.8792737732.

The spelling of 221312585 in words is "two hundred twenty-one million, three hundred twelve thousand, five hundred eighty-five".