21001105210 has 32 divisors (see below), whose sum is σ = 40392879120. Its totient is φ = 7833756672.

The previous prime is 21001105201. The next prime is 21001105241. The reversal of 21001105210 is 1250110012.

It can be written as a sum of positive squares in 8 ways, for example, as 14426652321 + 6574452889 = 120111^2 + 81083^2 .

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, 548149 + ... + 585208.

Almost surely, 2^21001105210 is an apocalyptic number.

21001105210 is a deficient number, since it is larger than the sum of its proper divisors (19391773910).

21001105210 is a wasteful number, since it uses less digits than its factorization.

21001105210 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1133490.

The product of its (nonzero) digits is 20, while the sum is 13.

Adding to 21001105210 its reverse (1250110012), we get a palindrome (22251215222).

The spelling of 21001105210 in words is "twenty-one billion, one million, one hundred five thousand, two hundred ten".