21021221011 has 8 divisors (see below), whose sum is σ = 24115601664. Its totient is φ = 17949677640.

The previous prime is 21021220973. The next prime is 21021221017. The reversal of 21021221011 is 11012212012.

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 21021221011 - 2¹¹ = 21021218963 is a prime.

It is a super-3 number, since 3×21021221011³ (a number of 32 digits) contains 333 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21021220982 and 21021221000.

It is not an unprimeable number, because it can be changed into a prime (21021221017) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5707345 + ... + 5711026.

It is an arithmetic number, because the mean of its divisors is an integer number (3014450208).

Almost surely, 2^21021221011 is an apocalyptic number.

21021221011 is a deficient number, since it is larger than the sum of its proper divisors (3094380653).

21021221011 is a wasteful number, since it uses less digits than its factorization.

21021221011 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11418641.

The product of its (nonzero) digits is 16, while the sum is 13.

Adding to 21021221011 its reverse (11012212012), we get a palindrome (32033433023).

The spelling of 21021221011 in words is "twenty-one billion, twenty-one million, two hundred twenty-one thousand, eleven".