21100021012 has 24 divisors (see below), whose sum is σ = 42996272256. Its totient is φ = 8872245408.

The previous prime is 21100021001. The next prime is 21100021021. The reversal of 21100021012 is 21012000112.

It is a self number, because there is not a number n which added to its sum of digits gives 21100021012.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 7107688 + ... + 7110655.

It is an arithmetic number, because the mean of its divisors is an integer number (1791511344).

Almost surely, 2^21100021012 is an apocalyptic number.

It is an amenable number.

21100021012 is an abundant number, since it is smaller than the sum of its proper divisors (21896251244).

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

21100021012 is a wasteful number, since it uses less digits than its factorization.

21100021012 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14218407 (or 14218405 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 10.

Adding to 21100021012 its reverse (21012000112), we get a palindrome (42112021124).

The spelling of 21100021012 in words is "twenty-one billion, one hundred million, twenty-one thousand, twelve".