21100222 has 48 divisors (see below), whose sum is σ = 39548880. Its totient is φ = 8363520.

The previous prime is 21100217. The next prime is 21100231. The reversal of 21100222 is 22200112.

It is a junction number, because it is equal to n+sod(n) for n = 21100199 and 21100208.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 59598 + ... + 59950.

It is an arithmetic number, because the mean of its divisors is an integer number (823935).

Almost surely, 2^21100222 is an apocalyptic number.

21100222 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

21100222 is a deficient number, since it is larger than the sum of its proper divisors (18448658).

21100222 is a wasteful number, since it uses less digits than its factorization.

21100222 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 409 (or 398 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 10.

The square root of 21100222 is about 4593.4977957979. The cubic root of 21100222 is about 276.3306179403.

Adding to 21100222 its reverse (22200112), we get a palindrome (43300334).

The spelling of 21100222 in words is "twenty-one million, one hundred thousand, two hundred twenty-two".