21001022211111 has 16 divisors (see below), whose sum is σ = 28036664918016. Its totient is φ = 13983032043936.

The previous prime is 21001022211109. The next prime is 21001022211119. The reversal of 21001022211111 is 11111222010012.

It is a happy number.

It is not a de Polignac number, because 21001022211111 - 2¹ = 21001022211109 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21001022211119) 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, 57426906 + ... + 57791448.

It is an arithmetic number, because the mean of its divisors is an integer number (1752291557376).

Almost surely, 2^{21001022211111} is an apocalyptic number.

21001022211111 is a deficient number, since it is larger than the sum of its proper divisors (7035642706905).

21001022211111 is a wasteful number, since it uses less digits than its factorization.

21001022211111 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 388702.

The product of its (nonzero) digits is 16, while the sum is 15.

Adding to 21001022211111 its reverse (11111222010012), we get a palindrome (32112244221123).

The spelling of 21001022211111 in words is "twenty-one trillion, one billion, twenty-two million, two hundred eleven thousand, one hundred eleven".