221110001001 has 24 divisors (see below), whose sum is σ = 328049007104. Its totient is φ = 143406974880.

The previous prime is 221110000919. The next prime is 221110001003. The reversal of 221110001001 is 100100011122.

It is a happy number.

It is not a de Polignac number, because 221110001001 - 2³¹ = 218962517353 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (9).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (221110001003) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 3527706 + ... + 3589836.

Almost surely, 2^221110001001 is an apocalyptic number.

It is an amenable number.

221110001001 is a deficient number, since it is larger than the sum of its proper divisors (106939006103).

221110001001 is a wasteful number, since it uses less digits than its factorization.

221110001001 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 72861 (or 72858 counting only the distinct ones).

The product of its (nonzero) digits is 4, while the sum is 9.

Adding to 221110001001 its reverse (100100011122), we get a palindrome (321210012123).

The spelling of 221110001001 in words is "two hundred twenty-one billion, one hundred ten million, one thousand, one".