1001221101 has 8 divisors (see below), whose sum is σ = 1483290560. Its totient is φ = 667480716.

The previous prime is 1001221097. The next prime is 1001221127. The reversal of 1001221101 is 1011221001.

It is a happy number.

It is not a de Polignac number, because 1001221101 - 2² = 1001221097 is a prime.

It is a super-3 number, since 3×1001221101³ (a number of 28 digits) contains 333 as substring.

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

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1001221301) 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, 18541105 + ... + 18541158.

It is an arithmetic number, because the mean of its divisors is an integer number (185411320).

Almost surely, 2^1001221101 is an apocalyptic number.

It is an amenable number.

1001221101 is a deficient number, since it is larger than the sum of its proper divisors (482069459).

1001221101 is an equidigital number, since it uses as much as digits as its factorization.

1001221101 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 37082272 (or 37082266 counting only the distinct ones).

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

The square root of 1001221101 is about 31642.0780133037. The cubic root of 1001221101 is about 1000.4068681026.

Adding to 1001221101 its reverse (1011221001), we get a palindrome (2012442102).

It can be divided in two parts, 10012 and 21101, that added together give a palindrome (31113).

The spelling of 1001221101 in words is "one billion, one million, two hundred twenty-one thousand, one hundred one".