21211111002101 has 4 divisors (see below), whose sum is σ = 21211530667500. Its totient is φ = 21210691336704.

The previous prime is 21211111002091. The next prime is 21211111002157. The reversal of 21211111002101 is 10120011111212.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 6535048027876 + 14676062974225 = 2556374^2 + 3830935^2 .

It is a cyclic number.

It is not a de Polignac number, because 21211111002101 - 2¹⁸ = 21211110739957 is a prime.

It is a super-2 number, since 2×21211111002101² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21211111004101) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 209756876 + ... + 209857973.

It is an arithmetic number, because the mean of its divisors is an integer number (5302882666875).

Almost surely, 2^{21211111002101} is an apocalyptic number.

It is an amenable number.

21211111002101 is a deficient number, since it is larger than the sum of its proper divisors (419665399).

21211111002101 is an equidigital number, since it uses as much as digits as its factorization.

21211111002101 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 419665398.

The product of its (nonzero) digits is 8, while the sum is 14.

Adding to 21211111002101 its reverse (10120011111212), we get a palindrome (31331122113313).

The spelling of 21211111002101 in words is "twenty-one trillion, two hundred eleven billion, one hundred eleven million, two thousand, one hundred one".