21011122011 has 16 divisors (see below), whose sum is σ = 30864227328. Its totient is φ = 12607932000.

The previous prime is 21011122009. The next prime is 21011122049. The reversal of 21011122011 is 11022111012.

It is not a de Polignac number, because 21011122011 - 2¹ = 21011122009 is a prime.

It is a super-2 number, since 2×21011122011² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21011122091) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3148651 + ... + 3155316.

It is an arithmetic number, because the mean of its divisors is an integer number (1929014208).

Almost surely, 2^21011122011 is an apocalyptic number.

21011122011 is a deficient number, since it is larger than the sum of its proper divisors (9853105317).

21011122011 is a wasteful number, since it uses less digits than its factorization.

21011122011 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6304082.

The product of its (nonzero) digits is 8, while the sum is 12.

Adding to 21011122011 its reverse (11022111012), we get a palindrome (32033233023).

The spelling of 21011122011 in words is "twenty-one billion, eleven million, one hundred twenty-two thousand, eleven".