20729517 has 8 divisors (see below), whose sum is σ = 27670560. Its totient is φ = 13804080.

The previous prime is 20729503. The next prime is 20729531. The reversal of 20729517 is 71592702.

It is an interprime number because it is at equal distance from previous prime (20729503) and next prime (20729531).

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

It is not a de Polignac number, because 20729517 - 2⁷ = 20729389 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20729567) 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, 334 + ... + 6447.

It is an arithmetic number, because the mean of its divisors is an integer number (3458820).

Almost surely, 2^20729517 is an apocalyptic number.

It is an amenable number.

20729517 is a deficient number, since it is larger than the sum of its proper divisors (6941043).

20729517 is a wasteful number, since it uses less digits than its factorization.

20729517 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7803.

The product of its (nonzero) digits is 8820, while the sum is 33.

The square root of 20729517 is about 4552.9679331179. The cubic root of 20729517 is about 274.7027841234.

The spelling of 20729517 in words is "twenty million, seven hundred twenty-nine thousand, five hundred seventeen".