21200021012 has 12 divisors (see below), whose sum is σ = 38713082016. Its totient is φ = 10139140440.

The previous prime is 21200021009. The next prime is 21200021027. The reversal of 21200021012 is 21012000212.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 21200020984 and 21200021002.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 115217414 + ... + 115217597.

It is an arithmetic number, because the mean of its divisors is an integer number (3226090168).

Almost surely, 2^21200021012 is an apocalyptic number.

It is an amenable number.

21200021012 is a deficient number, since it is larger than the sum of its proper divisors (17513061004).

21200021012 is a wasteful number, since it uses less digits than its factorization.

21200021012 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 230435038 (or 230435036 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 11.

Adding to 21200021012 its reverse (21012000212), we get a palindrome (42212021224).

The spelling of 21200021012 in words is "twenty-one billion, two hundred million, twenty-one thousand, twelve".