68505821 has 2 divisors, whose sum is σ = 68505822. Its totient is φ = 68505820.

The previous prime is 68505817. The next prime is 68505847. The reversal of 68505821 is 12850586.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 59136100 + 9369721 = 7690^2 + 3061^2 .

It is a cyclic number.

It is not a de Polignac number, because 68505821 - 2² = 68505817 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 (68505421) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 34252910 + 34252911.

It is an arithmetic number, because the mean of its divisors is an integer number (34252911).

Almost surely, 2^68505821 is an apocalyptic number.

It is an amenable number.

68505821 is a deficient number, since it is larger than the sum of its proper divisors (1).

68505821 is an equidigital number, since it uses as much as digits as its factorization.

68505821 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 19200, while the sum is 35.

The square root of 68505821 is about 8276.8243306234. The cubic root of 68505821 is about 409.1750634969.

The spelling of 68505821 in words is "sixty-eight million, five hundred five thousand, eight hundred twenty-one".