21221020111210 has 8 divisors (see below), whose sum is σ = 38197836200196. Its totient is φ = 8488408044480.

The previous prime is 21221020111201. The next prime is 21221020111243. The reversal of 21221020111210 is 1211102012212.

It can be written as a sum of positive squares in 2 ways, for example, as 21082340585601 + 138679525609 = 4591551^2 + 372397^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1061051005551 + ... + 1061051005570.

Almost surely, 2^{21221020111210} is an apocalyptic number.

21221020111210 is a deficient number, since it is larger than the sum of its proper divisors (16976816088986).

21221020111210 is a wasteful number, since it uses less digits than its factorization.

21221020111210 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2122102011128.

The product of its (nonzero) digits is 32, while the sum is 16.

Adding to 21221020111210 its reverse (1211102012212), we get a palindrome (22432122123422).

The spelling of 21221020111210 in words is "twenty-one trillion, two hundred twenty-one billion, twenty million, one hundred eleven thousand, two hundred ten".