81920029 has 8 divisors (see below), whose sum is σ = 83476800. Its totient is φ = 80373216.

The previous prime is 81920023. The next prime is 81920053. The reversal of 81920029 is 92002918.

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

It is a cyclic number.

It is not a de Polignac number, because 81920029 - 2³ = 81920021 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81920021) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 15297 + ... + 19945.

It is an arithmetic number, because the mean of its divisors is an integer number (10434600).

Almost surely, 2^81920029 is an apocalyptic number.

It is an amenable number.

81920029 is a deficient number, since it is larger than the sum of its proper divisors (1556771).

81920029 is a wasteful number, since it uses less digits than its factorization.

81920029 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4979.

The product of its (nonzero) digits is 2592, while the sum is 31.

The square root of 81920029 is about 9050.9684012265. The cubic root of 81920029 is about 434.3068699039.

The spelling of 81920029 in words is "eighty-one million, nine hundred twenty thousand, twenty-nine".