21010221011 has 8 divisors (see below), whose sum is σ = 22880622240. Its totient is φ = 19176138432.

The previous prime is 21010220999. The next prime is 21010221053. The reversal of 21010221011 is 11012201012.

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

It is a cyclic number.

It is not a de Polignac number, because 21010221011 - 2⁶ = 21010220947 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21010220983 and 21010221001.

It is not an unprimeable number, because it can be changed into a prime (21010221611) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 9078455 + ... + 9080768.

It is an arithmetic number, because the mean of its divisors is an integer number (2860077780).

Almost surely, 2^21010221011 is an apocalyptic number.

21010221011 is a deficient number, since it is larger than the sum of its proper divisors (1870401229).

21010221011 is a wasteful number, since it uses less digits than its factorization.

21010221011 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18159325.

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

Adding to 21010221011 its reverse (11012201012), we get a palindrome (32022422023).

The spelling of 21010221011 in words is "twenty-one billion, ten million, two hundred twenty-one thousand, eleven".