21212219999 has 16 divisors (see below), whose sum is σ = 22548595968. Its totient is φ = 19885821312.

The previous prime is 21212219983. The next prime is 21212220011. The reversal of 21212219999 is 99991221212.

It is a cyclic number.

It is not a de Polignac number, because 21212219999 - 2⁴ = 21212219983 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21212216999) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 10162934 + ... + 10165020.

It is an arithmetic number, because the mean of its divisors is an integer number (1409287248).

Almost surely, 2^21212219999 is an apocalyptic number.

21212219999 is a deficient number, since it is larger than the sum of its proper divisors (1336375969).

21212219999 is a wasteful number, since it uses less digits than its factorization.

21212219999 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4174.

The product of its digits is 104976, while the sum is 47.

The spelling of 21212219999 in words is "twenty-one billion, two hundred twelve million, two hundred nineteen thousand, nine hundred ninety-nine".