100012221 has 24 divisors (see below), whose sum is σ = 149118840. Its totient is φ = 64544256.

The previous prime is 100012217. The next prime is 100012223. The reversal of 100012221 is 122210001.

It can be written as a sum of positive squares in 4 ways, for example, as 34644996 + 65367225 = 5886^2 + 8085^2 .

It is not a de Polignac number, because 100012221 - 2² = 100012217 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 (100012223) 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, 76945 + ... + 78233.

It is an arithmetic number, because the mean of its divisors is an integer number (6213285).

Almost surely, 2^100012221 is an apocalyptic number.

It is an amenable number.

100012221 is a deficient number, since it is larger than the sum of its proper divisors (49106619).

100012221 is a wasteful number, since it uses less digits than its factorization.

100012221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1565 (or 1562 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 9.

The square root of 100012221 is about 10000.6110313320. The cubic root of 100012221 is about 464.1777908768.

Adding to 100012221 its reverse (122210001), we get a palindrome (222222222).

The spelling of 100012221 in words is "one hundred million, twelve thousand, two hundred twenty-one".