67770221 has 2 divisors, whose sum is σ = 67770222. Its totient is φ = 67770220.

The previous prime is 67770217. The next prime is 67770239. The reversal of 67770221 is 12207776.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 48804196 + 18966025 = 6986^2 + 4355^2 .

It is a cyclic number.

It is not a de Polignac number, because 67770221 - 2² = 67770217 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 (67760221) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33885110 + 33885111.

It is an arithmetic number, because the mean of its divisors is an integer number (33885111).

Almost surely, 2^67770221 is an apocalyptic number.

It is an amenable number.

67770221 is a deficient number, since it is larger than the sum of its proper divisors (1).

67770221 is an equidigital number, since it uses as much as digits as its factorization.

67770221 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 8232, while the sum is 32.

The square root of 67770221 is about 8232.2670632093. The cubic root of 67770221 is about 407.7052469508.

Adding to 67770221 its reverse (12207776), we get a palindrome (79977997).

The spelling of 67770221 in words is "sixty-seven million, seven hundred seventy thousand, two hundred twenty-one".