100011001221 has 48 divisors (see below), whose sum is σ = 153657174528. Its totient is φ = 62596800000.

The previous prime is 100011001217. The next prime is 100011001243. The reversal of 100011001221 is 122100110001.

It is a happy number.

It is not a de Polignac number, because 100011001221 - 2² = 100011001217 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 (100011001721) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 1066221 + ... + 1156221.

It is an arithmetic number, because the mean of its divisors is an integer number (3201191136).

Almost surely, 2^100011001221 is an apocalyptic number.

It is an amenable number.

100011001221 is a deficient number, since it is larger than the sum of its proper divisors (53646173307).

100011001221 is a wasteful number, since it uses less digits than its factorization.

100011001221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 90162 (or 90159 counting only the distinct ones).

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

Adding to 100011001221 its reverse (122100110001), we get a palindrome (222111111222).

The spelling of 100011001221 in words is "one hundred billion, eleven million, one thousand, two hundred twenty-one".