81137347 has 2 divisors, whose sum is σ = 81137348. Its totient is φ = 81137346.

The previous prime is 81137333. The next prime is 81137359. The reversal of 81137347 is 74373118.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 81137347 - 2¹⁹ = 80613059 is a prime.

It is a super-3 number, since 3×81137347³ (a number of 25 digits) contains 333 as substring.

It is not a weakly prime, because it can be changed into another prime (81137317) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40568673 + 40568674.

It is an arithmetic number, because the mean of its divisors is an integer number (40568674).

Almost surely, 2^81137347 is an apocalyptic number.

81137347 is a deficient number, since it is larger than the sum of its proper divisors (1).

81137347 is an equidigital number, since it uses as much as digits as its factorization.

81137347 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 14112, while the sum is 34.

The square root of 81137347 is about 9007.6271570264. The cubic root of 81137347 is about 432.9192868880.

The spelling of 81137347 in words is "eighty-one million, one hundred thirty-seven thousand, three hundred forty-seven".