67312981 has 2 divisors, whose sum is σ = 67312982. Its totient is φ = 67312980.

The previous prime is 67312963. The next prime is 67313011. The reversal of 67312981 is 18921376.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 51710481 + 15602500 = 7191^2 + 3950^2 .

It is a cyclic number.

It is not a de Polignac number, because 67312981 - 2⁷ = 67312853 is a prime.

It is a super-2 number, since 2×67312981² = 9062074822212722, which contains 22 as substring.

It is a Chen prime.

It is equal to p_3969181 and since 67312981 and 3969181 have the same sum of digits, it is a Honaker prime.

It is a self number, because there is not a number n which added to its sum of digits gives 67312981.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (67312961) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33656490 + 33656491.

It is an arithmetic number, because the mean of its divisors is an integer number (33656491).

Almost surely, 2^67312981 is an apocalyptic number.

It is an amenable number.

67312981 is a deficient number, since it is larger than the sum of its proper divisors (1).

67312981 is an equidigital number, since it uses as much as digits as its factorization.

67312981 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 18144, while the sum is 37.

The square root of 67312981 is about 8204.4488541279. The cubic root of 67312981 is about 406.7862593562.

The spelling of 67312981 in words is "sixty-seven million, three hundred twelve thousand, nine hundred eighty-one".