212331100021 has 2 divisors, whose sum is σ = 212331100022. Its totient is φ = 212331100020.

The previous prime is 212331099989. The next prime is 212331100049. The reversal of 212331100021 is 120001133212.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 118532849796 + 93798250225 = 344286^2 + 306265^2 .

It is a cyclic number.

It is not a de Polignac number, because 212331100021 - 2⁵ = 212331099989 is a prime.

It is a super-2 number, since 2×212331100021² (a number of 23 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 212331099968 and 212331100004.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (212331106021) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 106165550010 + 106165550011.

It is an arithmetic number, because the mean of its divisors is an integer number (106165550011).

Almost surely, 2^212331100021 is an apocalyptic number.

It is an amenable number.

212331100021 is a deficient number, since it is larger than the sum of its proper divisors (1).

212331100021 is an equidigital number, since it uses as much as digits as its factorization.

212331100021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 72, while the sum is 16.

Adding to 212331100021 its reverse (120001133212), we get a palindrome (332332233233).

The spelling of 212331100021 in words is "two hundred twelve billion, three hundred thirty-one million, one hundred thousand, twenty-one".