20638617 has 8 divisors (see below), whose sum is σ = 28966560. Its totient is φ = 13034880.

The previous prime is 20638603. The next prime is 20638619. The reversal of 20638617 is 71683602.

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

It is not a de Polignac number, because 20638617 - 2⁴ = 20638601 is a prime.

It is a super-3 number, since 3×20638617³ (a number of 23 digits) contains 333 as substring.

It is a Smith number, since the sum of its digits (33) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is not an unprimeable number, because it can be changed into a prime (20638619) 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, 180984 + ... + 181097.

It is an arithmetic number, because the mean of its divisors is an integer number (3620820).

Almost surely, 2^20638617 is an apocalyptic number.

It is an amenable number.

20638617 is a deficient number, since it is larger than the sum of its proper divisors (8327943).

20638617 is a wasteful number, since it uses less digits than its factorization.

20638617 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 362103.

The product of its (nonzero) digits is 12096, while the sum is 33.

The square root of 20638617 is about 4542.9744661400. The cubic root of 20638617 is about 274.3006671613.

It can be divided in two parts, 206386 and 17, that added together give a triangular number (206403 = T₆₄₂).

The spelling of 20638617 in words is "twenty million, six hundred thirty-eight thousand, six hundred seventeen".