67142707781 has 4 divisors (see below), whose sum is σ = 67143700812. Its totient is φ = 67141714752.

The previous prime is 67142707759. The next prime is 67142707873. The reversal of 67142707781 is 18770724176.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 19779890881 + 47362816900 = 140641^2 + 217630^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-67142707781 is a prime.

It is a super-2 number, since 2×67142707781² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (67142707081) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 387050 + ... + 533003.

It is an arithmetic number, because the mean of its divisors is an integer number (16785925203).

Almost surely, 2^67142707781 is an apocalyptic number.

It is an amenable number.

67142707781 is a deficient number, since it is larger than the sum of its proper divisors (993031).

67142707781 is an equidigital number, since it uses as much as digits as its factorization.

67142707781 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 993030.

The product of its (nonzero) digits is 921984, while the sum is 50.

The spelling of 67142707781 in words is "sixty-seven billion, one hundred forty-two million, seven hundred seven thousand, seven hundred eighty-one".