212111009021 has 2 divisors, whose sum is σ = 212111009022. Its totient is φ = 212111009020.

The previous prime is 212111009017. The next prime is 212111009051. The reversal of 212111009021 is 120900111212.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 211035496996 + 1075512025 = 459386^2 + 32795^2 .

It is a cyclic number.

It is not a de Polignac number, because 212111009021 - 2² = 212111009017 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 212111008984 and 212111009002.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (212111009051) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 106055504510 + 106055504511.

It is an arithmetic number, because the mean of its divisors is an integer number (106055504511).

Almost surely, 2^212111009021 is an apocalyptic number.

It is an amenable number.

212111009021 is a deficient number, since it is larger than the sum of its proper divisors (1).

212111009021 is an equidigital number, since it uses as much as digits as its factorization.

212111009021 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 20.

The spelling of 212111009021 in words is "two hundred twelve billion, one hundred eleven million, nine thousand, twenty-one".