221478611 has 8 divisors (see below), whose sum is σ = 235945920. Its totient is φ = 207292392.

The previous prime is 221478589. The next prime is 221478613. The reversal of 221478611 is 116874122.

It is a happy number.

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 221478611 - 2¹⁰ = 221477587 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (221478613) 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, 68645 + ... + 71798.

It is an arithmetic number, because the mean of its divisors is an integer number (29493240).

Almost surely, 2^221478611 is an apocalyptic number.

221478611 is a deficient number, since it is larger than the sum of its proper divisors (14467309).

221478611 is a wasteful number, since it uses less digits than its factorization.

221478611 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 140545.

The product of its digits is 5376, while the sum is 32.

The square root of 221478611 is about 14882.1574712808. The cubic root of 221478611 is about 605.0304936478.

The spelling of 221478611 in words is "two hundred twenty-one million, four hundred seventy-eight thousand, six hundred eleven".