21212011100020 has 72 divisors (see below), whose sum is σ = 48703665419136. Its totient is φ = 7756086978432.

The previous prime is 21212011099973. The next prime is 21212011100057. The reversal of 21212011100020 is 2000111021212.

It is a Harshad number since it is a multiple of its sum of digits (13).

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, 30116632 + ... + 30812911.

It is an arithmetic number, because the mean of its divisors is an integer number (676439797488).

Almost surely, 2^{21212011100020} is an apocalyptic number.

21212011100020 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21212011100020 is an abundant number, since it is smaller than the sum of its proper divisors (27491654319116).

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

21212011100020 is a wasteful number, since it uses less digits than its factorization.

21212011100020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 60929681 (or 60929666 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 13.

Adding to 21212011100020 its reverse (2000111021212), we get a palindrome (23212122121232).

The spelling of 21212011100020 in words is "twenty-one trillion, two hundred twelve billion, eleven million, one hundred thousand, twenty".