8172137381 has 2 divisors, whose sum is σ = 8172137382. Its totient is φ = 8172137380.

The previous prime is 8172137341. The next prime is 8172137411. The reversal of 8172137381 is 1837312718.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 7732564225 + 439573156 = 87935^2 + 20966^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-8172137381 is a prime.

It is a super-2 number, since 2×8172137381² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (8172137341) 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, 4086068690 + 4086068691.

It is an arithmetic number, because the mean of its divisors is an integer number (4086068691).

Almost surely, 2^8172137381 is an apocalyptic number.

It is an amenable number.

8172137381 is a deficient number, since it is larger than the sum of its proper divisors (1).

8172137381 is an equidigital number, since it uses as much as digits as its factorization.

8172137381 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 56448, while the sum is 41.

The square root of 8172137381 is about 90399.8748948249. The cubic root of 8172137381 is about 2014.2431079016.

The spelling of 8172137381 in words is "eight billion, one hundred seventy-two million, one hundred thirty-seven thousand, three hundred eighty-one".