20117729 has 8 divisors (see below), whose sum is σ = 20954112. Its totient is φ = 19293120.

The previous prime is 20117723. The next prime is 20117731. The reversal of 20117729 is 92771102.

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 20117729 - 2⁸ = 20117473 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20117723) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 632 + ... + 6374.

It is an arithmetic number, because the mean of its divisors is an integer number (2619264).

Almost surely, 2^20117729 is an apocalyptic number.

It is an amenable number.

20117729 is a deficient number, since it is larger than the sum of its proper divisors (836383).

20117729 is a wasteful number, since it uses less digits than its factorization.

20117729 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5887.

The product of its (nonzero) digits is 1764, while the sum is 29.

The square root of 20117729 is about 4485.2791440444. The cubic root of 20117729 is about 271.9733294567.

The spelling of 20117729 in words is "twenty million, one hundred seventeen thousand, seven hundred twenty-nine".