212249021 has 2 divisors, whose sum is σ = 212249022. Its totient is φ = 212249020.

The previous prime is 212249017. The next prime is 212249027. The reversal of 212249021 is 120942212.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 127351225 + 84897796 = 11285^2 + 9214^2 .

It is a cyclic number.

It is not a de Polignac number, because 212249021 - 2² = 212249017 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (212249027) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 106124510 + 106124511.

It is an arithmetic number, because the mean of its divisors is an integer number (106124511).

Almost surely, 2^212249021 is an apocalyptic number.

It is an amenable number.

212249021 is a deficient number, since it is larger than the sum of its proper divisors (1).

212249021 is an equidigital number, since it uses as much as digits as its factorization.

212249021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 576, while the sum is 23.

The square root of 212249021 is about 14568.7686851017. The cubic root of 212249021 is about 596.5065706916.

The spelling of 212249021 in words is "two hundred twelve million, two hundred forty-nine thousand, twenty-one".