20856719 has 8 divisors (see below), whose sum is σ = 22885632. Its totient is φ = 18888480.

The previous prime is 20856709. The next prime is 20856721. The reversal of 20856719 is 91765802.

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

It is not a de Polignac number, because 20856719 - 2²⁰ = 19808143 is a prime.

It is a super-2 number, since 2×20856719² = 870005454889922, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20856709) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 14447 + ... + 15824.

It is an arithmetic number, because the mean of its divisors is an integer number (2860704).

Almost surely, 2^20856719 is an apocalyptic number.

20856719 is a deficient number, since it is larger than the sum of its proper divisors (2028913).

20856719 is a wasteful number, since it uses less digits than its factorization.

20856719 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 30337.

The product of its (nonzero) digits is 30240, while the sum is 38.

The square root of 20856719 is about 4566.9156988059. The cubic root of 20856719 is about 275.2635226017.

The spelling of 20856719 in words is "twenty million, eight hundred fifty-six thousand, seven hundred nineteen".