221002001 has 8 divisors (see below), whose sum is σ = 241626144. Its totient is φ = 200466720.

The previous prime is 221001967. The next prime is 221002003. The reversal of 221002001 is 100200122.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-221002001 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 221002001.

It is not an unprimeable number, because it can be changed into a prime (221002003) 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, 16955 + ... + 27008.

It is an arithmetic number, because the mean of its divisors is an integer number (30203268).

Almost surely, 2^221002001 is an apocalyptic number.

It is an amenable number.

221002001 is a deficient number, since it is larger than the sum of its proper divisors (20624143).

221002001 is a wasteful number, since it uses less digits than its factorization.

221002001 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 44431.

The product of its (nonzero) digits is 8, while the sum is 8.

The square root of 221002001 is about 14866.1360480792. The cubic root of 221002001 is about 604.5961843217.

Adding to 221002001 its reverse (100200122), we get a palindrome (321202123).

It can be divided in two parts, 22 and 1002001, that multiplied together give a palindrome (22044022).

The spelling of 221002001 in words is "two hundred twenty-one million, two thousand, one".