20778317 has 8 divisors (see below), whose sum is σ = 23872512. Its totient is φ = 17715600.

The previous prime is 20778311. The next prime is 20778323. The reversal of 20778317 is 71387702.

It is an interprime number because it is at equal distance from previous prime (20778311) and next prime (20778323).

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

It is not a de Polignac number, because 20778317 - 2⁶ = 20778253 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 (20778311) 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, 6434 + ... + 9107.

It is an arithmetic number, because the mean of its divisors is an integer number (2984064).

Almost surely, 2^20778317 is an apocalyptic number.

It is an amenable number.

20778317 is a deficient number, since it is larger than the sum of its proper divisors (3094195).

20778317 is a wasteful number, since it uses less digits than its factorization.

20778317 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15739.

The product of its (nonzero) digits is 16464, while the sum is 35.

The square root of 20778317 is about 4558.3239244266. The cubic root of 20778317 is about 274.9181773100.

The spelling of 20778317 in words is "twenty million, seven hundred seventy-eight thousand, three hundred seventeen".