212615021 has 2 divisors, whose sum is σ = 212615022. Its totient is φ = 212615020.

The previous prime is 212615009. The next prime is 212615027. The reversal of 212615021 is 120516212.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 168870025 + 43744996 = 12995^2 + 6614^2 .

It is a cyclic number.

It is not a de Polignac number, because 212615021 - 2¹⁰ = 212613997 is a prime.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 212614984 and 212615002.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (212615027) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 106307510 + 106307511.

It is an arithmetic number, because the mean of its divisors is an integer number (106307511).

Almost surely, 2^212615021 is an apocalyptic number.

It is an amenable number.

212615021 is a deficient number, since it is larger than the sum of its proper divisors (1).

212615021 is an equidigital number, since it uses as much as digits as its factorization.

212615021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 240, while the sum is 20.

The square root of 212615021 is about 14581.3243911519. The cubic root of 212615021 is about 596.8492437046.

The spelling of 212615021 in words is "two hundred twelve million, six hundred fifteen thousand, twenty-one".