68221261 has 2 divisors, whose sum is σ = 68221262. Its totient is φ = 68221260.

The previous prime is 68221217. The next prime is 68221277. The reversal of 68221261 is 16212286.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 61921161 + 6300100 = 7869^2 + 2510^2 .

It is a cyclic number.

It is not a de Polignac number, because 68221261 - 2¹³ = 68213069 is a prime.

It is equal to p_4019590 and since 68221261 and 4019590 have the same sum of digits, it is a Honaker prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (68221211) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 34110630 + 34110631.

It is an arithmetic number, because the mean of its divisors is an integer number (34110631).

Almost surely, 2^68221261 is an apocalyptic number.

It is an amenable number.

68221261 is a deficient number, since it is larger than the sum of its proper divisors (1).

68221261 is an equidigital number, since it uses as much as digits as its factorization.

68221261 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2304, while the sum is 28.

The square root of 68221261 is about 8259.6162743798. The cubic root of 68221261 is about 408.6077324126.

The spelling of 68221261 in words is "sixty-eight million, two hundred twenty-one thousand, two hundred sixty-one".