211210111100021 has 4 divisors (see below), whose sum is σ = 230411030290944. Its totient is φ = 192009191909100.

The previous prime is 211210111099973. The next prime is 211210111100063. The reversal of 211210111100021 is 120001111012112.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 211210111100021 - 2²² = 211210106905717 is a prime.

It is a super-2 number, since 2×211210111100021² (a number of 29 digits) contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 211210111099969 and 211210111100005.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (211210111160021) 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, 9600459595445 + ... + 9600459595466.

It is an arithmetic number, because the mean of its divisors is an integer number (57602757572736).

Almost surely, 2^{211210111100021} is an apocalyptic number.

It is an amenable number.

211210111100021 is a deficient number, since it is larger than the sum of its proper divisors (19200919190923).

211210111100021 is a wasteful number, since it uses less digits than its factorization.

211210111100021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19200919190922.

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

Adding to 211210111100021 its reverse (120001111012112), we get a palindrome (331211222112133).

The spelling of 211210111100021 in words is "two hundred eleven trillion, two hundred ten billion, one hundred eleven million, one hundred thousand, twenty-one".