21010221101 has 4 divisors (see below), whose sum is σ = 21025659804. Its totient is φ = 20994782400.

The previous prime is 21010221073. The next prime is 21010221121. The reversal of 21010221101 is 10112201012.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 3008632201 + 18001588900 = 54851^2 + 134170^2 .

It is a cyclic number.

It is not a de Polignac number, because 21010221101 - 2¹⁴ = 21010204717 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21010221121) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 7717310 + ... + 7720031.

It is an arithmetic number, because the mean of its divisors is an integer number (5256414951).

Almost surely, 2^21010221101 is an apocalyptic number.

It is an amenable number.

21010221101 is a deficient number, since it is larger than the sum of its proper divisors (15438703).

21010221101 is a wasteful number, since it uses less digits than its factorization.

21010221101 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15438702.

The product of its (nonzero) digits is 8, while the sum is 11.

Adding to 21010221101 its reverse (10112201012), we get a palindrome (31122422113).

The spelling of 21010221101 in words is "twenty-one billion, ten million, two hundred twenty-one thousand, one hundred one".