67637644673681 has 2 divisors, whose sum is σ = 67637644673682. Its totient is φ = 67637644673680.

The previous prime is 67637644673609. The next prime is 67637644673689. The reversal of 67637644673681 is 18637644673676.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 62244841411600 + 5392803262081 = 7889540^2 + 2322241^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-67637644673681 is a prime.

It is a super-2 number, since 2×67637644673681² (a number of 28 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 67637644673599 and 67637644673608.

It is not a weakly prime, because it can be changed into another prime (67637644673689) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33818822336840 + 33818822336841.

It is an arithmetic number, because the mean of its divisors is an integer number (33818822336841).

Almost surely, 2^{67637644673681} is an apocalyptic number.

It is an amenable number.

67637644673681 is a deficient number, since it is larger than the sum of its proper divisors (1).

67637644673681 is an equidigital number, since it uses as much as digits as its factorization.

67637644673681 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3072577536, while the sum is 74.

The spelling of 67637644673681 in words is "sixty-seven trillion, six hundred thirty-seven billion, six hundred forty-four million, six hundred seventy-three thousand, six hundred eighty-one".