65870221 has 2 divisors, whose sum is σ = 65870222. Its totient is φ = 65870220.

The previous prime is 65870197. The next prime is 65870237. The reversal of 65870221 is 12207856.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 61622500 + 4247721 = 7850^2 + 2061^2 .

It is a cyclic number.

It is not a de Polignac number, because 65870221 - 2⁹ = 65869709 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (65870521) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 32935110 + 32935111.

It is an arithmetic number, because the mean of its divisors is an integer number (32935111).

Almost surely, 2^65870221 is an apocalyptic number.

It is an amenable number.

65870221 is a deficient number, since it is larger than the sum of its proper divisors (1).

65870221 is an equidigital number, since it uses as much as digits as its factorization.

65870221 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 6720, while the sum is 31.

The square root of 65870221 is about 8116.0471289908. The cubic root of 65870221 is about 403.8589453819.

The spelling of 65870221 in words is "sixty-five million, eight hundred seventy thousand, two hundred twenty-one".