21212011100021 has 16 divisors (see below), whose sum is σ = 24248895467520. Its totient is φ = 18176776697520.

The previous prime is 21212011099973. The next prime is 21212011100057. The reversal of 21212011100021 is 12000111021212.

It is a de Polignac number, because none of the positive numbers 2^k-21212011100021 is a prime.

It is a super-2 number, since 2×21212011100021² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21212011099969 and 21212011100005.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21212011100521) 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, 543223520 + ... + 543262566.

It is an arithmetic number, because the mean of its divisors is an integer number (1515555966720).

Almost surely, 2^{21212011100021} is an apocalyptic number.

It is an amenable number.

21212011100021 is a deficient number, since it is larger than the sum of its proper divisors (3036884367499).

21212011100021 is a wasteful number, since it uses less digits than its factorization.

21212011100021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 58184.

The product of its (nonzero) digits is 16, while the sum is 14.

Adding to 21212011100021 its reverse (12000111021212), we get a palindrome (33212122121233).

The spelling of 21212011100021 in words is "twenty-one trillion, two hundred twelve billion, eleven million, one hundred thousand, twenty-one".