21212300109 has 32 divisors (see below), whose sum is σ = 37974472704. Its totient is φ = 10171730880.

The previous prime is 21212300101. The next prime is 21212300111. The reversal of 21212300109 is 90100321212.

It is not a de Polignac number, because 21212300109 - 2³ = 21212300101 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21212300101) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 3528849 + ... + 3534854.

It is an arithmetic number, because the mean of its divisors is an integer number (1186702272).

Almost surely, 2^21212300109 is an apocalyptic number.

It is an amenable number.

21212300109 is a deficient number, since it is larger than the sum of its proper divisors (16762172595).

21212300109 is a wasteful number, since it uses less digits than its factorization.

21212300109 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7063737.

The product of its (nonzero) digits is 216, while the sum is 21.

It can be divided in two parts, 212 and 12300109, that added together give a palindrome (12300321).

The spelling of 21212300109 in words is "twenty-one billion, two hundred twelve million, three hundred thousand, one hundred nine".