68212181537 has 4 divisors (see below), whose sum is σ = 68454929796. Its totient is φ = 67969433280.

The previous prime is 68212181533. The next prime is 68212181567. The reversal of 68212181537 is 73518121286.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 73518121286 = 2 ⋅36759060643.

It can be written as a sum of positive squares in 2 ways, for example, as 24994345216 + 43217836321 = 158096^2 + 207889^2 .

It is a cyclic number.

It is not a de Polignac number, because 68212181537 - 2² = 68212181533 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (68212181533) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 121373708 + ... + 121374269.

It is an arithmetic number, because the mean of its divisors is an integer number (17113732449).

Almost surely, 2^68212181537 is an apocalyptic number.

It is an amenable number.

68212181537 is a deficient number, since it is larger than the sum of its proper divisors (242748259).

68212181537 is a wasteful number, since it uses less digits than its factorization.

68212181537 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 242748258.

The product of its digits is 161280, while the sum is 44.

The spelling of 68212181537 in words is "sixty-eight billion, two hundred twelve million, one hundred eighty-one thousand, five hundred thirty-seven".