67693839721 has 2 divisors, whose sum is σ = 67693839722. Its totient is φ = 67693839720.

The previous prime is 67693839659. The next prime is 67693839743. The reversal of 67693839721 is 12793839676.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 45736527321 + 21957312400 = 213861^2 + 148180^2 .

It is a cyclic number.

It is not a de Polignac number, because 67693839721 - 2¹⁵ = 67693806953 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 67693839721.

It is not a weakly prime, because it can be changed into another prime (67693837721) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33846919860 + 33846919861.

It is an arithmetic number, because the mean of its divisors is an integer number (33846919861).

Almost surely, 2^67693839721 is an apocalyptic number.

It is an amenable number.

67693839721 is a deficient number, since it is larger than the sum of its proper divisors (1).

67693839721 is an equidigital number, since it uses as much as digits as its factorization.

67693839721 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 20575296, while the sum is 61.

The spelling of 67693839721 in words is "sixty-seven billion, six hundred ninety-three million, eight hundred thirty-nine thousand, seven hundred twenty-one".