81538147219 has 2 divisors, whose sum is σ = 81538147220. Its totient is φ = 81538147218.

The previous prime is 81538147211. The next prime is 81538147267. The reversal of 81538147219 is 91274183518.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 81538147219 - 2³ = 81538147211 is a prime.

It is a super-2 number, since 2×81538147219² (a number of 23 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (81538147211) 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, 40769073609 + 40769073610.

It is an arithmetic number, because the mean of its divisors is an integer number (40769073610).

Almost surely, 2^81538147219 is an apocalyptic number.

81538147219 is a deficient number, since it is larger than the sum of its proper divisors (1).

81538147219 is an equidigital number, since it uses as much as digits as its factorization.

81538147219 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 483840, while the sum is 49.

The spelling of 81538147219 in words is "eighty-one billion, five hundred thirty-eight million, one hundred forty-seven thousand, two hundred nineteen".