21101011122021 has 16 divisors (see below), whose sum is σ = 28542741433920. Its totient is φ = 13863616905600.

The previous prime is 21101011121989. The next prime is 21101011122043. The reversal of 21101011122021 is 12022111010112.

It is a happy number.

It is not a de Polignac number, because 21101011122021 - 2⁵ = 21101011121989 is a prime.

It is a super-2 number, since 2×21101011122021² (a number of 27 digits) contains 22 as substring.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21101011122091) 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, 37989430 + ... + 38540871.

It is an arithmetic number, because the mean of its divisors is an integer number (1783921339620).

Almost surely, 2^{21101011122021} is an apocalyptic number.

It is an amenable number.

21101011122021 is a deficient number, since it is larger than the sum of its proper divisors (7441730311899).

21101011122021 is a wasteful number, since it uses less digits than its factorization.

21101011122021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 76531636.

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

Adding to 21101011122021 its reverse (12022111010112), we get a palindrome (33123122132133).

The spelling of 21101011122021 in words is "twenty-one trillion, one hundred one billion, eleven million, one hundred twenty-two thousand, twenty-one".