81629147705 has 16 divisors (see below), whose sum is σ = 111956584320. Its totient is φ = 55970253312.

The previous prime is 81629147701. The next prime is 81629147711. The reversal of 81629147705 is 50774192618.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 81629147705 - 2² = 81629147701 is a prime.

It is not an unprimeable number, because it can be changed into a prime (81629147701) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 460442 + ... + 612588.

It is an arithmetic number, because the mean of its divisors is an integer number (6997286520).

Almost surely, 2^81629147705 is an apocalyptic number.

It is an amenable number.

81629147705 is a deficient number, since it is larger than the sum of its proper divisors (30327436615).

81629147705 is a wasteful number, since it uses less digits than its factorization.

81629147705 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 167488.

The product of its (nonzero) digits is 846720, while the sum is 50.

The spelling of 81629147705 in words is "eighty-one billion, six hundred twenty-nine million, one hundred forty-seven thousand, seven hundred five".