68055521 has 2 divisors, whose sum is σ = 68055522. Its totient is φ = 68055520.

The previous prime is 68055479. The next prime is 68055523. The reversal of 68055521 is 12555086.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 64577296 + 3478225 = 8036^2 + 1865^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-68055521 is a prime.

Together with 68055523, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (68055523) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 34027760 + 34027761.

It is an arithmetic number, because the mean of its divisors is an integer number (34027761).

Almost surely, 2^68055521 is an apocalyptic number.

It is an amenable number.

68055521 is a deficient number, since it is larger than the sum of its proper divisors (1).

68055521 is an equidigital number, since it uses as much as digits as its factorization.

68055521 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 12000, while the sum is 32.

The square root of 68055521 is about 8249.5770194598. The cubic root of 68055521 is about 408.2765670173.

The spelling of 68055521 in words is "sixty-eight million, fifty-five thousand, five hundred twenty-one".