21010211205 has 16 divisors (see below), whose sum is σ = 33629226624. Its totient is φ = 11201149760.

The previous prime is 21010211197. The next prime is 21010211227. The reversal of 21010211205 is 50211201012.

It is not a de Polignac number, because 21010211205 - 2³ = 21010211197 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 227889 + ... + 306518.

It is an arithmetic number, because the mean of its divisors is an integer number (2101826664).

Almost surely, 2^21010211205 is an apocalyptic number.

It is an amenable number.

21010211205 is a deficient number, since it is larger than the sum of its proper divisors (12619015419).

21010211205 is a wasteful number, since it uses less digits than its factorization.

21010211205 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 537036.

The product of its (nonzero) digits is 40, while the sum is 15.

Adding to 21010211205 its reverse (50211201012), we get a palindrome (71221412217).

The spelling of 21010211205 in words is "twenty-one billion, ten million, two hundred eleven thousand, two hundred five".