20717919 has 12 divisors (see below), whose sum is σ = 30958200. Its totient is φ = 13335504.

The previous prime is 20717903. The next prime is 20717927. The reversal of 20717919 is 91971702.

It is not a de Polignac number, because 20717919 - 2⁴ = 20717903 is a prime.

It is a super-2 number, since 2×20717919² = 858464335381122, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20717969) 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 11 ways as a sum of consecutive naturals, for example, 39429 + ... + 39950.

It is an arithmetic number, because the mean of its divisors is an integer number (2579850).

Almost surely, 2^20717919 is an apocalyptic number.

20717919 is a gapful number since it is divisible by the number (29) formed by its first and last digit.

20717919 is a deficient number, since it is larger than the sum of its proper divisors (10240281).

20717919 is a wasteful number, since it uses less digits than its factorization.

20717919 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 79414 (or 79411 counting only the distinct ones).

The product of its (nonzero) digits is 7938, while the sum is 36.

The square root of 20717919 is about 4551.6940802299. The cubic root of 20717919 is about 274.6515432245.

The spelling of 20717919 in words is "twenty million, seven hundred seventeen thousand, nine hundred nineteen".