212657639 has 2 divisors, whose sum is σ = 212657640. Its totient is φ = 212657638.

The previous prime is 212657623. The next prime is 212657647. The reversal of 212657639 is 936756212.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 212657639 - 2⁴ = 212657623 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 212657596 and 212657605.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (212657689) 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, 106328819 + 106328820.

It is an arithmetic number, because the mean of its divisors is an integer number (106328820).

Almost surely, 2^212657639 is an apocalyptic number.

212657639 is a deficient number, since it is larger than the sum of its proper divisors (1).

212657639 is an equidigital number, since it uses as much as digits as its factorization.

212657639 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 136080, while the sum is 41.

The square root of 212657639 is about 14582.7857078132. The cubic root of 212657639 is about 596.8891198801.

The spelling of 212657639 in words is "two hundred twelve million, six hundred fifty-seven thousand, six hundred thirty-nine".