81351696635 has 32 divisors (see below), whose sum is σ = 106860943872. Its totient is φ = 58962919680.

The previous prime is 81351696581. The next prime is 81351696637. The reversal of 81351696635 is 53669615318.

It is not a de Polignac number, because 81351696635 - 2³⁰ = 80277954811 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81351696637) 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 in 31 ways as a sum of consecutive naturals, for example, 25524512 + ... + 25527698.

It is an arithmetic number, because the mean of its divisors is an integer number (3339404496).

Almost surely, 2^81351696635 is an apocalyptic number.

81351696635 is a deficient number, since it is larger than the sum of its proper divisors (25509247237).

81351696635 is a wasteful number, since it uses less digits than its factorization.

81351696635 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4643.

The product of its digits is 3499200, while the sum is 53.

The spelling of 81351696635 in words is "eighty-one billion, three hundred fifty-one million, six hundred ninety-six thousand, six hundred thirty-five".