21011120221 has 32 divisors (see below), whose sum is σ = 26135278848. Its totient is φ = 16447656960.

The previous prime is 21011120219. The next prime is 21011120237. The reversal of 21011120221 is 12202111012.

It is not a de Polignac number, because 21011120221 - 2¹ = 21011120219 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (13).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21011120521) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 7104075 + ... + 7107031.

It is an arithmetic number, because the mean of its divisors is an integer number (816727464).

Almost surely, 2^21011120221 is an apocalyptic number.

It is an amenable number.

21011120221 is a deficient number, since it is larger than the sum of its proper divisors (5124158627).

21011120221 is a wasteful number, since it uses less digits than its factorization.

21011120221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3781.

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

Adding to 21011120221 its reverse (12202111012), we get a palindrome (33213231233).

The spelling of 21011120221 in words is "twenty-one billion, eleven million, one hundred twenty thousand, two hundred twenty-one".