68645221 has 2 divisors, whose sum is σ = 68645222. Its totient is φ = 68645220.

The previous prime is 68645207. The next prime is 68645273. The reversal of 68645221 is 12254686.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 39062500 + 29582721 = 6250^2 + 5439^2 .

It is a cyclic number.

It is not a de Polignac number, because 68645221 - 2¹³ = 68637029 is a prime.

It is a super-2 number, since 2×68645221² = 9424332732277682, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (68645321) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 34322610 + 34322611.

It is an arithmetic number, because the mean of its divisors is an integer number (34322611).

Almost surely, 2^68645221 is an apocalyptic number.

It is an amenable number.

68645221 is a deficient number, since it is larger than the sum of its proper divisors (1).

68645221 is an equidigital number, since it uses as much as digits as its factorization.

68645221 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 23040, while the sum is 34.

The square root of 68645221 is about 8285.2411552109. The cubic root of 68645221 is about 409.4524139363.

It can be divided in two parts, 68 and 645221, that multiplied together give a triangular number (43875028 = T₉₃₆₇).

The spelling of 68645221 in words is "sixty-eight million, six hundred forty-five thousand, two hundred twenty-one".