221501001 has 8 divisors (see below), whose sum is σ = 296212384. Its totient is φ = 147228480.

The previous prime is 221500999. The next prime is 221501009. The reversal of 221501001 is 100105122.

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

It is not a de Polignac number, because 221501001 - 2¹ = 221500999 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 (221501009) 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, 108535 + ... + 110556.

It is an arithmetic number, because the mean of its divisors is an integer number (37026548).

Almost surely, 2^221501001 is an apocalyptic number.

It is an amenable number.

221501001 is a deficient number, since it is larger than the sum of its proper divisors (74711383).

221501001 is a wasteful number, since it uses less digits than its factorization.

221501001 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 219431.

The product of its (nonzero) digits is 20, while the sum is 12.

The square root of 221501001 is about 14882.9096953519. The cubic root of 221501001 is about 605.0508811338.

Adding to 221501001 its reverse (100105122), we get a palindrome (321606123).

The spelling of 221501001 in words is "two hundred twenty-one million, five hundred one thousand, one".