100021212 has 72 divisors (see below), whose sum is σ = 264135872. Its totient is φ = 31881600.

The previous prime is 100021199. The next prime is 100021223. The reversal of 100021212 is 212120001.

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

It is a junction number, because it is equal to n+sod(n) for n = 100021194 and 100021203.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 80637 + ... + 81867.

Almost surely, 2^100021212 is an apocalyptic number.

100021212 is a gapful number since it is divisible by the number (12) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 100021212, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (132067936).

100021212 is an abundant number, since it is smaller than the sum of its proper divisors (164114660).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

100021212 is a wasteful number, since it uses less digits than its factorization.

100021212 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1339 (or 1334 counting only the distinct ones).

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

The square root of 100021212 is about 10001.0605437623. The cubic root of 100021212 is about 464.1917001685.

Adding to 100021212 its reverse (212120001), we get a palindrome (312141213).

The spelling of 100021212 in words is "one hundred million, twenty-one thousand, two hundred twelve".