68217557 has 2 divisors, whose sum is σ = 68217558. Its totient is φ = 68217556.

The previous prime is 68217553. The next prime is 68217601. The reversal of 68217557 is 75571286.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 65141041 + 3076516 = 8071^2 + 1754^2 .

It is a cyclic number.

It is not a de Polignac number, because 68217557 - 2² = 68217553 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 (68217553) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 34108778 + 34108779.

It is an arithmetic number, because the mean of its divisors is an integer number (34108779).

Almost surely, 2^68217557 is an apocalyptic number.

It is an amenable number.

68217557 is a deficient number, since it is larger than the sum of its proper divisors (1).

68217557 is an equidigital number, since it uses as much as digits as its factorization.

68217557 is an evil number, because the sum of its binary digits is even.

The product of its digits is 117600, while the sum is 41.

The square root of 68217557 is about 8259.3920478447. The cubic root of 68217557 is about 408.6003373063.

The spelling of 68217557 in words is "sixty-eight million, two hundred seventeen thousand, five hundred fifty-seven".