68553521 has 2 divisors, whose sum is σ = 68553522. Its totient is φ = 68553520.

The previous prime is 68553491. The next prime is 68553557. The reversal of 68553521 is 12535586.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 67881121 + 672400 = 8239^2 + 820^2 .

It is a cyclic number.

It is not a de Polignac number, because 68553521 - 2¹⁴ = 68537137 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (68553581) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 34276760 + 34276761.

It is an arithmetic number, because the mean of its divisors is an integer number (34276761).

Almost surely, 2^68553521 is an apocalyptic number.

It is an amenable number.

68553521 is a deficient number, since it is larger than the sum of its proper divisors (1).

68553521 is an equidigital number, since it uses as much as digits as its factorization.

68553521 is an evil number, because the sum of its binary digits is even.

The product of its digits is 36000, while the sum is 35.

The square root of 68553521 is about 8279.7053691541. The cubic root of 68553521 is about 409.2700097949.

The spelling of 68553521 in words is "sixty-eight million, five hundred fifty-three thousand, five hundred twenty-one".