81636704245 has 16 divisors (see below), whose sum is σ = 98155677312. Its totient is φ = 65181695040.

The previous prime is 81636704239. The next prime is 81636704251. The reversal of 81636704245 is 54240763618.

It is an interprime number because it is at equal distance from previous prime (81636704239) and next prime (81636704251).

It is not a de Polignac number, because 81636704245 - 2¹⁷ = 81636573173 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 81636704195 and 81636704204.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 14217075 + ... + 14222815.

It is an arithmetic number, because the mean of its divisors is an integer number (6134729832).

Almost surely, 2^81636704245 is an apocalyptic number.

It is an amenable number.

81636704245 is a deficient number, since it is larger than the sum of its proper divisors (16518973067).

81636704245 is a wasteful number, since it uses less digits than its factorization.

81636704245 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10812.

The product of its (nonzero) digits is 967680, while the sum is 46.

The spelling of 81636704245 in words is "eighty-one billion, six hundred thirty-six million, seven hundred four thousand, two hundred forty-five".