1001101221 has 16 divisors (see below), whose sum is σ = 1483732800. Its totient is φ = 667121904.

The previous prime is 1001101217. The next prime is 1001101261. The reversal of 1001101221 is 1221011001.

It is a happy number.

It is not a de Polignac number, because 1001101221 - 2² = 1001101217 is a prime.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1001101261) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 73570 + ... + 86108.

It is an arithmetic number, because the mean of its divisors is an integer number (92733300).

Almost surely, 2^1001101221 is an apocalyptic number.

It is an amenable number.

1001101221 is a deficient number, since it is larger than the sum of its proper divisors (482631579).

1001101221 is a wasteful number, since it uses less digits than its factorization.

1001101221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15505 (or 15499 counting only the distinct ones).

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

The square root of 1001101221 is about 31640.1836435884. The cubic root of 1001101221 is about 1000.3669390060.

Adding to 1001101221 its reverse (1221011001), we get a palindrome (2222112222).

The spelling of 1001101221 in words is "one billion, one million, one hundred one thousand, two hundred twenty-one".