81513336427 has 2 divisors, whose sum is σ = 81513336428. Its totient is φ = 81513336426.

The previous prime is 81513336413. The next prime is 81513336433. The reversal of 81513336427 is 72463331518.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 81513336427 - 2⁷ = 81513336299 is a prime.

It is a super-2 number, since 2×81513336427² (a number of 23 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (81513336727) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40756668213 + 40756668214.

It is an arithmetic number, because the mean of its divisors is an integer number (40756668214).

Almost surely, 2^81513336427 is an apocalyptic number.

81513336427 is a deficient number, since it is larger than the sum of its proper divisors (1).

81513336427 is an equidigital number, since it uses as much as digits as its factorization.

81513336427 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 362880, while the sum is 43.

The spelling of 81513336427 in words is "eighty-one billion, five hundred thirteen million, three hundred thirty-six thousand, four hundred twenty-seven".