81201729 has 8 divisors (see below), whose sum is σ = 123736000. Its totient is φ = 46400976.

The previous prime is 81201721. The next prime is 81201733. The reversal of 81201729 is 92710218.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 81201729 - 2³ = 81201721 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 81201696 and 81201705.

It is not an unprimeable number, because it can be changed into a prime (81201721) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1933354 + ... + 1933395.

It is an arithmetic number, because the mean of its divisors is an integer number (15467000).

Almost surely, 2^81201729 is an apocalyptic number.

It is an amenable number.

81201729 is a deficient number, since it is larger than the sum of its proper divisors (42534271).

81201729 is a wasteful number, since it uses less digits than its factorization.

81201729 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3866759.

The product of its (nonzero) digits is 2016, while the sum is 30.

The square root of 81201729 is about 9011.2001975320. The cubic root of 81201729 is about 433.0337629038.

The spelling of 81201729 in words is "eighty-one million, two hundred one thousand, seven hundred twenty-nine".