81306402851 has 2 divisors, whose sum is σ = 81306402852. Its totient is φ = 81306402850.

The previous prime is 81306402847. The next prime is 81306402901. The reversal of 81306402851 is 15820460318.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 81306402851 - 2² = 81306402847 is a prime.

It is a super-2 number, since 2×81306402851² (a number of 23 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (81306401851) 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 as a sum of consecutive naturals, namely, 40653201425 + 40653201426.

It is an arithmetic number, because the mean of its divisors is an integer number (40653201426).

Almost surely, 2^81306402851 is an apocalyptic number.

81306402851 is a deficient number, since it is larger than the sum of its proper divisors (1).

81306402851 is an equidigital number, since it uses as much as digits as its factorization.

81306402851 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 46080, while the sum is 38.

The spelling of 81306402851 in words is "eighty-one billion, three hundred six million, four hundred two thousand, eight hundred fifty-one".