81017642029 has 4 divisors (see below), whose sum is σ = 81122997340. Its totient is φ = 80912286720.

The previous prime is 81017642023. The next prime is 81017642051. The reversal of 81017642029 is 92024671018.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 34016269225 + 47001372804 = 184435^2 + 216798^2 .

It is a cyclic number.

It is not a de Polignac number, because 81017642029 - 2³ = 81017642021 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 81017641982 and 81017642000.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81017642021) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 52676502 + ... + 52678039.

It is an arithmetic number, because the mean of its divisors is an integer number (20280749335).

Almost surely, 2^81017642029 is an apocalyptic number.

It is an amenable number.

81017642029 is a deficient number, since it is larger than the sum of its proper divisors (105355311).

81017642029 is a wasteful number, since it uses less digits than its factorization.

81017642029 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 105355310.

The product of its (nonzero) digits is 48384, while the sum is 40.

The spelling of 81017642029 in words is "eighty-one billion, seventeen million, six hundred forty-two thousand, twenty-nine".