20728101 has 8 divisors (see below), whose sum is σ = 27688320. Its totient is φ = 13793312.

The previous prime is 20728093. The next prime is 20728109. The reversal of 20728101 is 10182702.

It is an interprime number because it is at equal distance from previous prime (20728093) and next prime (20728109).

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 20728101 - 2³ = 20728093 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20728109) 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, 4365 + ... + 7778.

It is an arithmetic number, because the mean of its divisors is an integer number (3461040).

Almost surely, 2^20728101 is an apocalyptic number.

It is an amenable number.

20728101 is a deficient number, since it is larger than the sum of its proper divisors (6960219).

20728101 is a wasteful number, since it uses less digits than its factorization.

20728101 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12715.

The product of its (nonzero) digits is 224, while the sum is 21.

The square root of 20728101 is about 4552.8124275002. The cubic root of 20728101 is about 274.6965291457.

The spelling of 20728101 in words is "twenty million, seven hundred twenty-eight thousand, one hundred one".